Olefinic Bond Research Articles

Nickel-Catalyzed Remote C(sp3)–N/O Bond Formation of Alkenes with Unactivated Amines and Alcohols

Transition metal-catalyzed remote hydrofunctionalization of alkenes is an efficient method to realize C(sp3)–H functionalization. However, remote hydrofunctionalization of alkenes with unactivated amines and alcohols has not been successfully developed to date. Herein, we report an efficient nickel-catalyzed remote hydroamination and hydroetherification of alkenes with unactivated amines and alcohols, accessing a series of gem-diamine and N,O-acetal derivatives in good to high yields (up to 93%) and exclusive regioselectivities. The mechanistic investigations and DFT computations indicated that the use of 2-iodo-2-methylpropane (tBuI) as both a mild hydride source and radical precursor was essential to afford the remote functionalized products. This research work provides an efficient method to install an amino or alkoxyl group at the C(sp3)–H position that is far from the double bond of alkenes.

Palm Oil Valorization through the Oxidative Cleavage of Unsaturated Fatty Acids with Ru-Carbon Catalysts

Palm oil valorization for the production of azelaic acid, highly demanded for the treatment of skin cancer, was performed through the oxidative cleavage of unsaturated fatty acids. In this reaction, olefinic bonds are broken to yield carboxylic and dicarboxylic acids. To do so, carbon black and carbon micrometric particles were functionalized with polydopamine to form complexes with Ru. These Ru-carbon catalysts were fully characterized before catalytic tests, where triglycerides within palm oil were transformed into fatty acid methyl esters first and then incorporated in our catalytic system formed by H2O/MeCN/AcOEt. After adding NaIO4 and N-methylmorpholine N-oxide (oxidizing agents), our Ru-carbon catalysts reached a complete >99% conversion in 5 h of reaction at room temperature with yields of azelaic acid around 85%. Although Ru species were found in the liquid phase during the reaction, the solid catalysts managed to recover them to keep the same catalytic activity for five recycling tests. Therefore, our Ru-carbon catalysts open a novel route for the production of a high-value-added product with medicinal applications from a cheap feedstock such as palm oil.

Mechanism of chlorotriflamidation of vinylsilanes with <i>N</i>,<i>N</i>-dichlorotriflamide

The mechanism of the reaction of vinylsilanes with N , N -dichlorotriflamide and the effect of a substituent at the silicon atom on the reaction course and on the charge distribution in substrates and their carbon analogues were studied by DFT method. The C=C bond in vinylsilanes and alkenes is polarized in the opposite way. The reaction proceeds in two stages: chlorination of the substrate with the formation of a chloronium ion, and its opening at the Cβ-Cl bond by the N -chlorotriflamide anion. Transition states of two stages were calculated. The reaction products are hydrolyzed to NH-derivatives; their IR spectra and supramolecular structure, including cyclic and linear dimers, calculated in the gas phase and in a polar medium, were studied.

Exploring the peri- and stereo- selectivities of the cycloaddition reaction of 2-(2- dimethylaminovinyl)-1-benzopyran-4-one with N-phenylmaleimide (NPM) and dimethylacetylenedicarboxylate (DMAD) - A DFT study

The [4 + 2] cycloaddition reactions of 2-styrylchromones have been predominantly described as one of the efficient methods for the synthesis of xanthones-a prominent class of tricyclic molecules that occur widely in nature. These xanthones are well known for their pharmacological activities especially their role as anti-cancer agents in the medicinal world. In this study, the mechanistic insight into the unusual (peri- and stereo-) selectivities of the reaction of 2-(2-dimethylaminovinyl)-1-benzopyran-4-one (A1) with N-phenylmaleimide (NPM) and dimethylacetylenedicarboxylate (DMAD) has been studied using density functional theory (DFT) at the M06-2X/6-311G (d, p) level of theory. The reaction of A1 and NPM in dimethylformamide (DMF) is periselective towards the initial formation of a [4 + 2] cycloadduct and stereoselectively in an exo fashion with an activation energy of 6.8kcalmol−1 and a rate constant of 6.43×107s−1 which occurs about 878 million times faster than the closest competing pathway for the initial [2 + 2] cycloaddition fashion with an activation energy of 19.0kcalmol−1 and a rate constant of 7.32×10−2s−1. For the substituent effect on the reaction, the reaction selectivity is still maintained where the exo intermediate remains the most kinetically favored cycloadduct. However, the magnitude of the barriers increases slightly with a margin of about 0.1−4.8kcalmol for the electron-donating groups (EDGs) in the order; strong EDGs (OH < NH2 < OCH3) < weak EDGs (<Ph) and 5.3−6.4kcalmol for electron-withdrawing groups in the order; strong EWGs (CF3) < weak EWGs (Cl < Br). On the other hand, DMAD periselectively adds across the amino substituted olefinic bond of A1 via an initial [2 + 2] stepwise cycloaddition fashion followed by an intramolecular rearrangement to form the xanthone product. The rate constant of the rate-determining step in the pathway for the formation of the kinetically favored [4 + 2] cycloadduct with an activation barrier of 17.3kcalmol−1 is 1.29s−1 which occurs about 373,000 times slower than the most preferred pathway affording a [2 + 2] cycloadduct with an activation barrier of 9.7kcalmol−1 and a rate constant of 4.81×105s−1. Both reactions are normal electron-demand cycloaddition reactions and are kinetically controlled.

Biological Consequences of Vanadium Effects on Formation of Reactive Oxygen Species and Lipid Peroxidation

Lipid peroxidation (LPO), a process that affects human health, can be induced by exposure to vanadium salts and compounds. LPO is often exacerbated by oxidation stress, with some forms of vanadium providing protective effects. The LPO reaction involves the oxidation of the alkene bonds, primarily in polyunsaturated fatty acids, in a chain reaction to form radical and reactive oxygen species (ROS). LPO reactions typically affect cellular membranes through direct effects on membrane structure and function as well as impacting other cellular functions due to increases in ROS. Although LPO effects on mitochondrial function have been studied in detail, other cellular components and organelles are affected. Because vanadium salts and complexes can induce ROS formation both directly and indirectly, the study of LPO arising from increased ROS should include investigations of both processes. This is made more challenging by the range of vanadium species that exist under physiological conditions and the diverse effects of these species. Thus, complex vanadium chemistry requires speciation studies of vanadium to evaluate the direct and indirect effects of the various species that are present during vanadium exposure. Undoubtedly, speciation is important in assessing how vanadium exerts effects in biological systems and is likely the underlying cause for some of the beneficial effects reported in cancerous, diabetic, neurodegenerative conditions and other diseased tissues impacted by LPO processes. Speciation of vanadium, together with investigations of ROS and LPO, should be considered in future biological studies evaluating vanadium effects on the formation of ROS and on LPO in cells, tissues, and organisms as discussed in this review.

Potential of derivation of a series of C6–C14 1-alkene skeletal oxidation mechanisms on the basis of reaction rate rules

Olefins, accounting for one-fifth proportion of gasoline fuel, are also essential intermediates in the combustion of large hydrocarbons and vital precursors of large polycyclic aromatic hydrocarbons and soot. The unsaturated C = C bond of alkenes renders a more complex low-temperature reaction scheme compared with their corresponding n-alkanes. Thus, it is of great necessity to obtain a thorough knowledge of the chemical kinetics of alkenes. However, the studies on the chemical kinetics of long-chain olefins are far from sufficient. In this work, a collection of skeletal oxidation mechanisms for 1-alkenes from 1-hexene (C6H12-1) to 1-tetradecene (C14H28-1) were constructed in light of recent advances in skeletal mechanism construction for fuels sharing similar structures based on reaction rate rules. For each 1-alkene, the skeletal mechanism includes ∼54 species and ∼216 reactions. Meanwhile, the effect of the C = C double bond was evaluated by conducting a bond dissociation energy calculation to assist the skeletal mechanism construction and derivation. It is discovered that the allylic position is preferred for H-atom abstraction reactions owing to its lowest bond dissociation energy among different locations for all heavy 1-alkenes. Furthermore, the reactions of OH addition to the C = C bond become important at low temperatures, which competes with the H-atom abstraction reactions. This results in the lower reactivity of 1-alkenes compared with corresponding n-alkanes at low temperatures. The acquired skeletal mechanisms were validated against extensive experimental data including laminar flame speeds, ignition delay times in shock tubes, and key species concentrations in jet-stirred reactors, flow reactors, and premixed laminar flames. The good agreements between experiments and simulations demonstrate the prediction capability of all the skeletal mechanisms of 1-alkenes although minor discrepancies exist in the concentration predictions for C2–C3 species, which might stem from a highly reduced C2–C3 sub-mechanism being utilized in the present mechanism.

Crucial role of alkali metal ions and Si/Al ratio in selective adsorption of 1-octene using faujasite zeolites

Linear α-olefins (LAOs) are conventionally purified from paraffins via energy-intensive superfractionation. Adsorptive separation with zeolite-based adsorbents is a promising alternative to distillation for olefin/paraffin purification. However, very few zeolites with different Si/Al ratios and metal ion types have been tested to separate LAOs in the liquid phase. In this study, we investigated the ability of various alkali metal ion-exchanged faujasites with different Si/Al ratios to separate 1-octene/n-octane mixtures. We prepared low-silica X (LSX), X, and Y zeolites loaded with Li+, Na+, K+, and Rb+ via ion exchange in an aqueous solution. The 1-octene adsorption capacities and selectivities were analyzed via liquid-phase batch adsorption experiments. Among LSX, X, and Y exchanged with the Na+ and Li+, LSX which had the lowest Si/Al ratios exhibited the highest selectivity. The 1-octene selectivities for LSX were in the following order: Rb+ ≈ K+ < Na+ < Li+. LiLSX demonstrated the greatest separation efficiency among the zeolites owing to the presence of the largest number of cation sites and the highest charge density of Li+. The affinity constants calculated from the Langmuir-type adsorption isotherms and enthalpies of adsorption suggest that cation–π interactions between the C = C bond in olefins and metal ions influence selective adsorption. Density functional theory calculations support this theory of intermolecular interactions. Furthermore, a series of adsorption and desorption breakthrough experiments using a column packed with LiLSX validated its applicability for separating 1-octene and n-octane. We believe these adsorbents can be modified further and widely applied in the purification of higher olefins from chemical and biochemical products.

(Arylimido)niobium(V)–Alkylidenes as the Catalysts for Ring-Opening Metathesis Polymerization (ROMP) of Cyclic Olefins: Z-Specific ROMP of Cyclooctene by Nb(CHSiMe3)(NC6H5)[OC(CF3)3](PMe3)2

(Arylimido)niobium(V)–alkylidene complexes, Nb(CHSiMe3)(NAr)[OC(CF3)3](PMe3)2 (Ar = C6H5 (4), 2,6-F2C6H3, C6F5 (6)), Nb(CHSiMe3)(N-2,6-Cl2C6H3)(OC6F5)(PMe3)2 (7), and Nb(CHSiMe3)(N-2,6-F2C6H3)(OC6Cl5)(PMe3)2, have been prepared and identified. The pentafluorophenylimido analogue 6 and 7 showed superior catalytic activities for the ring-opening metathesis polymerization (ROMP) of norbornene (TOF = 56.1, 53.7 s–1, respectively, at 25 °C) and the activities increased at 50 °C (TOF ≥ 352 s–1). The prepared alkylidenes catalyzed the ROMP of cis-cyclooctene (COE), and the activity increased at high temperature (up to 80 °C). The Z-specific ROMP of COE has been demonstrated especially by the phenylimido analogue 4 at 80 °C, affording polymers possessing olefinic double bonds with exclusive cis selectivity (99%).

Systematic In Vitro Metabolic Profiling of the OXIZID Synthetic Cannabinoids BZO-4en-POXIZID, BZO-POXIZID, 5F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID.

A new class of synthetic cannabinoids termed OXIZIDs has recently emerged on the recreational drug market. In order to continue the detection of new drugs in biological specimens, the identification of metabolites is essential. The aim of this study was to elucidate the metabolites of BZO-4en-POXIZID produced in human liver microsomes (HLMs) and human hepatocyte incubations and to compare the results with closely related analogs using the same experimental setup. Each drug was incubated for 1 h in HLM and BZO-4en-POXIZID was also incubated in human hepatocytes for up to 3 h. Subsequently, the incubates were analyzed by liquid chromatography-high-resolution mass spectrometry. BZO-4en-POXIZID metabolites were obtained in the incubation with HLMs and human hepatocytes, via the metabolic pathways of dihydrodiol formation, hydroxylation, reduction of the alkene bond and glucuronidation. The major metabolic pathway was found to be dihydrodiol formation at the pentenyl tail moiety. BZO-POXIZID, 5 F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID underwent similar metabolism to those reported in the literature, via the metabolic pathways of N-dealkylation, hydroxylation, ketone formation and oxidative defluorination (to alcohol or carboxylic acid). The results suggest that OXIZIDs are mainly metabolized at the N-alkyl moiety and the major metabolic pathways are hydroxylation when the N-alkyl moiety is a simple hydrocarbon, whereas functional-group-specific pathways (dihydrodiol formation and oxidative defluorination) are preferred when the moiety contains specific functional groups (alkene or fluoro), as has been observed for other synthetic cannabinoids. The major metabolites generated via these major metabolic pathways should serve as useful analytical targets for urine analysis. Furthermore, the higher abundance of glucuronidated metabolite suggests that enzymatic hydrolysis of glucuronides may be necessary for urine analysis to increase phase I metabolite concentration and improve detection.

Cationic Tantalum Hydrides Catalyze Hydrogenolysis and Alkane Metathesis Reactions of Paraffins and Polyethylene.

Sulfated aluminum oxide (SAO), a high surface area material containing sulfate anions that behave like weakly coordinating anions, reacts with Ta(═CHtBu)(CH2tBu)3 to form [Ta(CH2tBu)2(O-)2][SAO] (1). Subsequent treatment with H2 forms Ta-H+ sites supported on SAO that are active in hydrogenolysis and alkane metathesis reactions. In both reactions Ta-H+ is more active than related neutral Ta-H sites supported on silica. This reaction chemistry extends to melts of high-density polyethylene (HDPE), where Ta-H+ converts 30% of a low molecular weight HDPE (Mn = 2.5 kg mol-1; Đ = 3.6) to low molecular weight paraffins under hydrogenolysis conditions. Under alkane metathesis conditions Ta-H+ converts this HDPE to a high MW fraction (Mn = 6.2 kDa; Đ = 2.3) and low molecular weight alkane products (C13-C32). These results show that incorporating charge as a design element in supported d0 metal hydrides is a viable strategy to increase the reaction rate in challenging reactions involving reorganization of C-C bonds in alkanes.

Stoichiometric Alkane and Aldehyde Hydroxylation Reactions Mediated by In Situ Generated Iron(III)-Iodosylbenzene Adduct

Previously synthesized and spectroscopically characterized mononuclear nonheme, low-spin iron(III)-iodosylbenzene complex bearing a bidentate pyridyl-benzimidazole ligands has been investigated in alkane and aldehyde oxidation reactions. The in situ generated Fe(III) iodosylbenzene intermediate is a reactive oxidant capable of activating the benzylic C-H bond of alkane. Its electrophilic character was confirmed by using substituted benzaldehydes and a modified ligand framework containing electron-donating (Me) substituents. Furthermore, the results of kinetic isotope experiments (KIE) using deuterated substrate indicate that the C-H activation can be interpreted through a tunneling-like HAT mechanism. Based on the results of the kinetic measurements and the relatively high KIE values, we can conclude that the activation of the C-H bond mediated by iron(III)-iodosylbenzene adducts is the rate-determining step.

Modulating the Energetics of C–H Bond Activation in Methane by Utilizing Metalated Porphyrinic Metal–Organic Frameworks

In recent years, much effort has been directed toward utilizing metal-organic frameworks (MOFs) for activating C-H bonds of light alkanes. The energy demanding steps involved in the catalytic pathway are the formation of metal-oxo species and the subsequent cleavage of the C-H bonds of alkanes. With the intention of exploring the tunability of the activation barriers involved in the catalytic pathway of methane hydroxylation, we have employed density functional theory to model metalated porphyrinic MOFs (MOF-525(M)). We find that the heavier congeners down a particular group have high exothermic oxo-formation enthalpies ΔHO and hence are associated with low N2O activation barriers. Independent analyses of activation barriers and structure-activity relationship leads to the conclusion that MOF-525(Ru) and MOF-525(Ir) can act as an effective catalysts for methane hydroxylation. Hence, ΔHO has been found to act as a guide, in the first place, in choosing the optimum catalyst for methane hydroxylation from a large set of available systems.

Simultaneous two-photon intravital imaging of viscosity and superoxide radical anion by a styrylpyridinium-based fluorescent probe

Simultaneous sensing of cellular microenvironment parameters and redox signaling molecules by a single fluorescent probe allows an efficient access to numerous applications ranging from convenient diagnostic assays to investigation on their pathophysiological roles and cross-link. Focusing on a lack of efficient molecule tools for simultaneous intravital imaging of mitochondrial viscosity and superoxide radical anion (O2•-), we bridged diethylaminobenzene with diphenylphosphinate-modified pyridinium moiety by an olefinic bond to construct a styrylpyridinium-based two-photon fluorescent probe V-OS. V-OS triggered a turn-on response either at 625 nm to viscosity which blocks intramolecular rotation, or at 530 nm to O2•-via nucleophilic attack of O2•- followed by 1,6-elimination. With the aid of the two-photon probe, we not only identified the cross-talk between viscosity and O2•- but successfully mapped the burst of O2•- and the increased viscosity during either cellular ferroptosis process or cerebral ischemia reperfusion injury of living mice.

Discovery and Computational Studies of Potent Covalent Kinase Inhibitors with α-Substituent Electrophiles Targeting Cysteine.

Both reversible noncovalent inhibitors and irreversible covalent inhibitors targeting tyrosine kinases have their disadvantages. The reversible covalent inhibitors with electrophilic group cyanoacrylamide as warheads reacting with cysteine residues could solve the dilemmas. However, there are still several unresolved issues regarding the electrophilic groups. In this manuscript, a series of EGFR inhibitors with double electron-withdrawing substituents introduced into the Cα position on the olefin bond were designed and synthesized. The binding structures and characteristics of inhibitors with the kinase in both the first noncovalent binding phase and the second covalent binding step were explored and combined with molecular docking and molecular dynamics simulations. Then, the reverse β-elimination reactions of the thiol-Michael adducts were investigated by applying density functional theory calculations. In addition, the effects of different electrophilic substituents of Cα on the binding between the inhibitors and kinase were elucidated. The results suggested that the electrophilicity and size of the electron-withdrawing groups play an important role in the specific interactions during the reaction. The compounds with the electron-withdrawing groups that had medium electrostatic and steric complementarity to the kinase active site could cooperatively stabilize the complexes and showed relatively good potent activities in the kinase assay experiment. The mechanical and structural information in this study could enhance our understanding of the functioning of the electron-withdrawing groups in the covalent inhibitors. The results might help to design efficient cysteine targeting inhibitors in the future.

Design and Synthesis of Scopoletin Sulfonate Derivatives as Potential Insecticidal Agents.

(1) Background: Scopoletin and scoparone, two naturally occurring coumarins, have garnered considerable attention and have been introduced to the market in China due to their high insecticidal efficacy and low toxicity. To investigate the structure-activity relationship of these coumarins, a series of scopoletin derivatives with aryl sulfate at C7 and different substitutes at C3 were designed and synthesized, and their insecticidal activity was studied. (2) Methods: A total of 28 new scopoletin derivatives were designed and synthesized. Most target compounds exhibited moderate insecticidal activity against the phytophagous mite Tetranychus cinnabarinus and the brine shrimp Artemia salina. (3) Results: Among these compounds, compounds 5a and 5j possessed the best insecticidal activities against T. cinnabarinus, with LC50 values of 57.0 and 20.0 μg/mL, respectively, whereas that of the control drug was 15.0 μg/mL. Compound 4j exhibited selective insecticidal activities against A. salina, with an LC50 value of 9.36 μg/mL, whereas its LC50 value against T. cinnabarinus was 93.0 μg/mL. The enzymatic inhibitory activity on acetylcholinesterase (AChE) showed a consistent tendency with the insecticidal activity. Further molecular docking analyses predicted the binding conformations of these compounds, which showed a good correlation between the insecticidal activity and the binding scores. (4) Conclusions: In general, a decreased electron cloud density of the Δ3,4 olefinic bond is beneficial for improving the insecticidal activity against both T. cinnabarinus and A. salina. In addition, naphthyl or benzene groups with a sulfate ester at the C7 position could further improve the insecticidal activity against A. salina. AChE was implied to be a site of action for potential insecticidal activity. The results provide insight into the rational design of a new generation of effective coumarin insecticides.

Revisiting the Burden Borne by Fumarase: Enzymatic Hydration of an Olefin.

Fumarate hydratase (FH) is a remarkable catalyst that decreases the free energy of the catalyzed reaction by 30 kcal mol-1, much larger than most exceptional enzymes with extraordinary catalytic rates. Two classes of FH are observed in nature: class-I and class-II, which have different folds, yet catalyze the same reversible hydration/dehydration reaction of the dicarboxylic acids fumarate/malate, with equal efficiencies. Using class-I FH from the hyperthermophilic archaeon Methanocaldococcus jannaschii (Mj) as a model along with comparative analysis with the only other available class-I FH structure from Leishmania major (Lm), we provide insights into the molecular mechanism of catalysis in this class of enzymes. The structure of MjFH apo-protein has been determined, revealing that large intersubunit rearrangements occur across apo- and holo-protein forms, with a largely preorganized active site for substrate binding. Site-directed mutagenesis of active site residues, kinetic analysis, and computational studies, including density functional theory (DFT) and natural population analysis, together show that residues interacting with the carboxylate group of the substrate play a pivotal role in catalysis. Our study establishes that an electrostatic network at the active site of class-I FH polarizes the substrate fumarate through interactions with its carboxylate groups, thereby permitting an easier addition of a water molecule across the olefinic bond. We propose a mechanism of catalysis in FH that occurs through transition-state stabilization involving the distortion of the electronic structure of the substrate olefinic bond mediated by the charge polarization of the bound substrate at the enzyme active site.

Chemoenzymatic Enantioselective Synthesis of the Hancock Alkaloids (S)- and (R)-Galipeine, (S)-Cuspareine, (S)-Galipinine, and (S)-Angustureine

AbstractThe enantioselective synthesis of the Hancock 1,2,3,4-tetrahydroquinoline alkaloids (S)-galipeine, (S)-cuspareine, (S)-galipinine, and (S)-angustureine and the nonnatural enantiomer (R)-galipeine is described herein. The target compounds were obtained in five steps from a racemic quinaldinic acid derived α-amino ester in overall yields of 21.2% to 37.5%. The synthetic route comprised two key steps: an enzymatic kinetic resolution to control the C-2 stereocenter, affording (R)- and (S)-α-amino esters as key chiral intermediates with 94% and 72% ee, respectively, and Wittig olefination of (R)- and (S)-α-amino aldehyde synthons with the corresponding phosphonium salts using a phase-transfer system (t-BuOH/CH2Cl2), thereby allowing the introduction of alkyl substituents at C-2. Finally, the enantioselective synthesis was concluded with the catalytic hydrogenation of olefinic bonds on the Wittig adducts to furnish the target Hancock alkaloids, including (R)-galipeine, whose synthesis is described here for the first time.

Three-component color-tunable room temperature afterglow doped materials through Förster-resonance energy transfer

A facile and versatile strategy for the development of room-temperature afterglow doped materials is constructed based on fluorescent molecules containing olefinic bonds by a mechanism of Förster-resonance energy transfer.

Photo-induced stereo- and regiospecific sulfonylation of C–C multiple bonds exploiting the dual reactivity of sulfonium iodate(i) species

The visible-light-directed stereospecific radical sulfonylation featuring the dual-reactivity of electrophilic reagent Me3SI(OAc)2 is realized for vinyl-sulfonyl functionalization of the C(sp)-H and C(sp2)-H π bond in alkynes and alkenes.

Rhodium-catalyzed atroposelective access to trisubstituted olefins via C-H bond olefination of diverse arenes.

The atroposelective synthesis of axially chiral acyclic olefins remains a daunting challenge due to their relatively lower racemization barriers, especially for trisubstituted ones. In this work, atroposelective C-H olefination has been realized for synthesis of open-chain trisubstituted olefins via C-H activation of two classes of (hetero)arenes in the coupling with sterically hindered alkynes. The employment of phenyl N-methoxycarbamates as arene reagents afforded phenol-tethered olefins, with the carbamate being a traceless directing group. The olefination of N-methoxy-2-indolylcarboxamides afforded the corresponding chiral olefin by circumventing the redox-neutral [4 + 2] annulation. The reactions proceeded with excellent Z/E selectivity, chemoselectivity, regioselectivity, and enantioselectivity in both hydroarylation systems.