Synthesis Of Trisubstituted Alkenes Research Articles

Julia‐Kocienski Olefination in the Synthesis of Trisubstituted Alkenes: Recent Progress

AbstractJulia‐Kocienski olefination, a coupling reaction between a carbonyl component and a sulfone partner, has emerged as a powerful synthetic tool in the preparation of several organic compounds. A number of interesting examples involving particularly the preparation of trisubstituted alkenes along with important observations regarding the stereoselectivity of those reactions have been recently reported. This reviewing work covers the literature for the period 2016–2022 and describes in a comprehensive way the progress and developments of Julia‐Kocienski olefination application in the synthesis of trisubstituted alkenes which serve as precursors of natural products and their analogs as well of pharmaceutically interesting/biologically important compounds. Moreover, key methodology results dealing with the investigation of the optimum conditions and stereoselectivities and new modifications and approaches are discussed.

Repurposing π Electrophilic Cyclization/Dealkylation for Group Transfer

AbstractA metal‐free regio‐ and stereocontrolled group‐transfer route toward the synthesis of trisubstituted alkenes is described. In this route, an electrophilic heterocyclization is followed by ring‐opening group transfer. Specifically, a thioboration reaction transforms readily available alkynyl sulfide precursors into alkenyl boronates and alkenyl sulfides with defined regio‐ and stereochemistry in one synthetic step using commercially available B‐chlorocatecholborane (ClBcat). Mechanistic studies identified the likely pathway as proceeding through zwitterionic rather than haloborated intermediates. The regio‐ and stereochemistry set in the initial cyclization step is preserved in the final acyclic alkene product, producing alkenes with up to four modifiable substituents with predictable regio‐ and stereochemistry. Downstream functionalization reactions showcase the versatility of the substitutions of the resulting alkenes. The mechanistic concept maps onto future reaction designs, given the abundance of known electrophiles and nucleophiles for electrophilic heterocyclization/dealkylation sequences.

Repurposing π Electrophilic Cyclization/Dealkylation for Group Transfer.

A metal-free regio- and stereocontrolled group-transfer route toward the synthesis of trisubstituted alkenes is described. In this route, an electrophilic heterocyclization is followed by ring-opening group transfer. Specifically, a thioboration reaction transforms readily available alkynyl sulfide precursors into alkenyl boronates and alkenyl sulfides with defined regio- and stereochemistry in one synthetic step using commercially available B-chlorocatecholborane (ClBcat). Mechanistic studies identified the likely pathway as proceeding through zwitterionic rather than haloborated intermediates. The regio- and stereochemistry set in the initial cyclization step is preserved in the final acyclic alkene product, producing alkenes with up to four modifiable substituents with predictable regio- and stereochemistry. Downstream functionalization reactions showcase the versatility of the substitutions of the resulting alkenes. The mechanistic concept maps onto future reaction designs, given the abundance of known electrophiles and nucleophiles for electrophilic heterocyclization/dealkylation sequences.

Synthesis of trisubstituted alkenes by Ni-catalyzed hydroalkylation of internal alkynes with cycloketone oxime esters.

A method for Ni-catalyzed hydroalkylation of internal alkynes with cycloketone oxime esters was developed. The reaction has a broad substrate scope. This hydroalkylation shows excellent regio- and stereo-selectivity. This method enables readily available starting materials to be used to access a range of cyano-substituted single-configuration trisubstituted alkenes. These are valuable feedstock chemicals and are widely used in synthetic and medicinal chemistry.

Synthesis of trisubstituted olefins via nickel-catalyzed decarboxylative hydroalkylation of internal alkynes

A novel NiH-catalyzed decarboxylative hydroalkylation of internal alkynes has been developed. Trisubstituted olefins were obtained in moderate to good yields with good regioselectivities. The reaction involves cis addition of NiH to the internal alkyne. The reaction shows good functional-group tolerance.

Stereoselective Synthesis of Trisubstituted Alkenes

Stereoselective Synthesis of Trisubstituted Alkenes

ChemInform Abstract: Recent Advances in the Ruthenium‐Catalyzed Hydroarylation of Alkynes with Aromatics: Synthesis of Trisubstituted Alkenes

AbstractReview: [21 refs.

ChemInform Abstract: Tf2NH‐Catalyzed, Highly Regio‐ and Stereo‐Selective Synthesis of Trisubstituted Alkenes and Indane Derivatives from Benzylic Alcohols and Alkenes.

AbstractThe reaction of benzylic alcohols with terminal 1,1‐disubstituted alkenes affords trisubstituted alkenes whereas the reaction of benzylic alcohols with 1,2‐disubstituted or 1,1,2‐trisubstituted alkenes provides indane derivatives.

ChemInform Abstract: Copper(I)‐Catalyzed (Z)‐β‐(Tosyloxy)alkenyl Iodide Synthesis from (Aryl)[(E)‐β‐(tosyloxy)alkenyl]iodonium Tosylates: Diversity‐Oriented Synthesis of Trisubstituted Alkenes.

AbstractThe treatment of iodonium tosylates (I) with a catalytic amount of CuCl leads to desired (Z)‐β‐(tosyloxy)alkenyl iodides (II), which are converted into tamoxifen intermediate (IV) and other trisubstituted alkenes (VII) and (X).

Copper(I)‐Catalyzed (Z)‐β‐(Tosyloxy)alkenyl Iodide Synthesis from (Aryl)[(E)‐β‐(tosyloxy)alkenyl]iodonium Tosylates: Diversity‐Oriented Synthesis of Trisubstituted Alkenes

AbstractThe first stereoselective synthesis of (Z)‐β‐(tosyloxy)alkenyl iodide has been developed from (aryl)[(E)‐β‐(tosyloxy)alkenyl]iodonium tosylates by using a CuI catalyst. The products of this reaction have been utilized for the diversity‐oriented synthesis of trisubstituted alkenes, and a formal synthesis of the anticancer compound (Z)‐tamoxifen is described.

Recent advances in the ruthenium-catalyzed hydroarylation of alkynes with aromatics: synthesis of trisubstituted alkenes

The hydroarylation of alkynes with substituted aromatics in the presence of a metal catalyst via chelation-assisted C-H bond activation is a powerful method to synthesize trisubstituted alkenes. Chelation-assisted C-H bond activation can be done by two ways: (a) an oxidative addition pathway and (b) a deprotonation pathway. Generally, a mixture of cis and trans stereoisomeric as well as regioisomeric trisubstituted alkenes was observed in an oxidative addition pathway. In the deprotonation pathway, the hydroarylation reaction can be done in a highly regio- and stereoselective manner, and enables preparation of the expected trisubstituted alkenes in a highly selective manner. Generally, ruthenium, rhodium and cobalt complexes are used as catalysts in the reaction. In this review, a ruthenium-catalyzed hydroarylation of alkynes with substituted aromatics is covered completely. The hydroarylation reaction of alkynes with amide, azole, carbamate, phosphine oxide, amine, acetyl, sulfoxide and sulphur directed aromatics is discussed.

ChemInform Abstract: Synthesis of Trisubstituted Alkenes via Direct Oxidative Arene—Alkene Coupling.

AbstractThe use of K2S2O8 in combination with Pd(OAc)2 as catalyst in a solvent mixture of AcOH and acetonitrile gives efficient access to trisubstituted alkenes.

Synthesis of Trisubstituted Alkenes via Direct Oxidative Arene–Alkene Coupling

The use of an inorganic oxidant with an acetic acid/acetonitrile solvent combination has been identified as optimal for direct arene/1,2-disubstituted alkene oxidative couplings, providing an efficient route to trisubstituted alkenes. The acetonitrile cosolvent dramatically accelerates the rate of reaction, and an insoluble inorganic oxidant limits unwanted oxidation of substrates. The scope of this procedure is illustrated with arenes and alkenes containing electron-donating and -withdrawing substituents resulting in a general synthetic strategy to trisubstituted alkenes. In situ ESI-MS analysis of the reaction components has identified the key Pd intermediates in the Fujiwara-Moritani catalytic cycle.

Palladium-Catalyzed Arylation of Enoates with Iodobenzene: Stereoselective Synthesis of Trisubstituted Olefins

The Heck reaction between E- and Z-enoates and iodobenzene was studied in the presence of Pd(OAc)2. The stereochemistry in resulting adducts was dependent on the enoate geometry (stereospecific reaction). Best yields were obtained from Z-isomers in acetone using Ag2CO3 as base. The main cationic palladium intermediates possibly involved in the catalytic cycle could be intercepted and characterized by electrospray ionization mass spectrometry (ESI-MS). The stereoselectivity observed was rationalized through the classic mechanism of the Heck reaction.

ChemInform Abstract: A Convergent Method for the Stereoselective Synthesis of Trisubstituted Alkenes.

A method for the stereoselective, convergent synthesis of trisubstituted alkenes has been developed. The procedure features the synthesis of allylic alcohols 9 by coupling an aldehyde with a vinyl organometallic reagent. Treatment of 9 with carbon disulfide and methyl iodide gave the intermediate allylic xanthates 10 that underwent facile [3,3]-sigmatropic rearrangement to give the dithiocarbonates 11 and 12, radical reduction of which gave the (E)-alkenes 13 as the major products

ChemInform Abstract: Arylethyne Bromoboration-Negishi Coupling Route to (E)- or (Z)-Aryl-Substituted Trisubstituted Alkenes of ≥ 98% Isomeric Purity. New Horizon in the Highly Selective Synthesis of Trisubstituted Alkenes.

ChemInform Abstract: Arylethyne Bromoboration-Negishi Coupling Route to (E)- or (Z)-Aryl-Substituted Trisubstituted Alkenes of ≥ 98% Isomeric Purity. New Horizon in the Highly Selective Synthesis of Trisubstituted Alkenes.

Reaction of N-Tosylated Imines with α,β-Acetylenic Ketones via Organozinc Species

A new procedure for stereoselective synthesis of trisubstituted alkenes by an one-pot, three-component reaction of N-tosylated imines with α,β-acetylenic ketones and organozinc species CF3COOZnEt was described. This reaction system provides β-branched Morita–Baylis–Hillman adducts with excellent yields in absence of any catalyst.

The allylic nucleophilic substitution of Morita–Baylis–Hillman acetates with isocyanides: a facile synthesis of trisubstituted olefins

Abstract Morita–Baylis–Hillman acetates undergo smooth allylic nucleophilic substitution (S N 2′) with tosylmethyl isocyanide (TosMIC) in the presence of a catalytic amount of BF 3 ·OEt 2 under mild conditions to furnish trisubstituted olefins in high yields with ( E )-stereoselectivity.

ChemInform Abstract: Development of a Palladium Catalyzed Addition of Boronic Acids to Alkynyl Esters: Synthesis of Trisubstituted Olefins as Single Isomers.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Development of a palladium catalyzed addition of boronic acids to alkynyl esters: synthesis of trisubstituted olefins as single isomers

Very small phosphine ligands allow access to single isomer trisubstituted olefins from alkynyl esters with complete control of both stereochemistry and regiochemistry. This method provides a convenient synthesis of single isomer trisubstituted olefins without requiring olefin templates.