Potassium Trifluoro Research Articles

Synthesis of sulfinamides via photocatalytic alkylation or arylation of sulfinylamine.

Sulfinamides are a versatile class of compounds that find applications in both organic synthesis and pharmaceuticals. Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. Commercially available potassium trifluoro(organo)borates and readily available sulfinyl amines are rationally used and converted to a series of alkyl or aryl sulfinamides in moderate to high yields. The reaction allows for the gram-scale preparation of sulfinamides. Moreover, sulfonimidamides, sulfonimidate esters and sulfonyl amides could be obtained in one pot.

Rational design of electrolyte solvation structure for stable cycling and fast charging lithium metal batteries

Developing dimethyl ether (DME)-based localized high-concentration electrolytes (LHCEs) is regarded as a promising approach to the application of lithium metal batteries (LMBs). However, LHCEs with DME: Li+ ratio ∼1.5: 1 still present many challenges including oxidation decomposition at high voltage and poor charging capability owing to low conductivity. Herein, we design an electrolyte consisting of lithium bis(fluorosulfonyl)imide (LiFSI, 1.1 M) in DME-hydrofluoroether (TTE) (DME: Li+ = 4: 1) with potassium trifluoro(trifluoromethyl)borate (PTB) as additive. PTB is found to strengthen the interaction between Li+ and DME/FSI− anions, which stabilizes the DME solvent against reduction/oxidation and facilitates the reduction reactivity of FSI− anions for stabilizing the interface of Li metal anode. Besides, the CF3BF3− anions of PTB involve in stabilizing LiNi0.9Mn0.05Co0.05O2 (NMC90) cathode by forming a LiF-rich interfacial layer. Notably, the Li||NMC90 (8 mAh cm−2 Li, ∼4.0 mAh cm−2 NMC90, ∼6 g electrolyte per Ah) battery can demonstrate a much-enhanced capacity retention of 84.1% after 170 cycles at charging current density of 4.0 mA cm−2 with a charge cut-off voltage of 4.5 V. This work offers a fundamental guidance in rational design solvation structures of electrolyte to improve the stability of electrode/electrolyte interface and kinetics for LMBs.

Synthesis of Heterocycles from Potassium Trifluoro(pyrimidin-4-yl)borate Salts

Synthesis of Heterocycles from Potassium Trifluoro(pyrimidin-4-yl)borate Salts

ChemInform Abstract: Suzuki—Miyaura Cross‐Coupling of Potassium Trifluoro(N‐methylheteroaryl)borates with Aryl and Heteroaryl Halides.

The synthesis of potassium trifluoro(N-methylheteroaryl)borates and their use in cross-coupling reactions with various aryl and heteroaryl halides to construct N-methyl heteroaryl-substituted aromatic and heteroaromatic compounds are reported.

Suzuki–Miyaura Cross-Coupling of Potassium Trifluoro(N-methylheteroaryl)borates with Aryl and Heteroaryl Halides

The synthesis of potassium trifluoro(N-methylheteroaryl)borates and their use in cross-coupling reactions with various aryl and heteroaryl halides to construct N-methyl heteroaryl-substituted aromatic and heteroaromatic compounds are reported.

Plant coumarins: XI. Cross coupling reactions with 2-(tosyl)oreoselone

The reaction of a linearly fused furocoumarin, oreoselone, with p-toluenesulfonyl chloride gave 2-tosyloreoselone which showed a high reactivity in palladium-catalyzed cross-coupling reactions with formation of a new carbon-carbon bond. 2-Tosyloreoselone reacted with terminal alkynes in the presence of Pd(PPh3)2Cl2 to give the corresponding 2-alkynylfuro[3,2-g]chromen-3-ones. 2-Aryl(hetaryl)alkynyloreoselones were obtained in high yield directly by palladium-catalyzed reaction of oreoselone with tosyl chloride and aryl(hetaryl)acetylenes. The reaction of 2-tosyloreoselone with aryl(hetaryl)boronic acids in the presence of palladium complexes with uni- and bidentate ligands, tetrabutylammonium bromide, and a base afforded 2-aryl(hetaryl)-substituted oreoselones. 2-Vinyloreoselone was synthesized from 2-tosyloreoselone and potassium trifluoro(vinyl)borate.

Design and synthesis of boron containing 2,4-disubstituted-phthalazin-1(2H)-one and 3,7-disubstituted-2H-benzo[b][1,4] oxazine derivatives as potential HGF-mimetic agents

We synthesized boron containing 2-(4-methoxybenzyl)-4-(4-(4,4,5,5-tetramethyl-1,3,2-dioaborolan-2-yl)phenyl) phthalazin-1(2H)-one 3 and 7-methyl-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-2H-benzo[b][1,4] oxazine 8. The reaction of compound 2 with B2pin2 using potassium acetate as the base and Pd(PPh3)2Cl2 as the catalyst, produced the corresponding boron-containing derivative 3 as a white solid in 65% yield. Alternatively, we have synthesized compound 8 as a yellow solid in 59% yield using the Miyaura borylation reaction. The potassium trifluoro(4-(-methyl-2H-benzo[b][1,4]oxazine-3-yl)phenylborate 9 was then obtained after treatment of 8 with aqueous solution of KF2H in methanol as white solid product in 60% yield. The biological activities of the synthetic compounds are currently being evaluated.

Room-Temperature Rhodium-Catalyzed Asymmetric 1,4-Addition of Potassium Trifluoro(organo)borates

For the first time the room-temperature rhodium-catalyzed asymmetric 1,4-addition of potassium aryltrifluoroborates to alpha,beta-unsaturated substrates is described. Thanks to the use of a chiral diene as ligand for rhodium and triethylamine as base, to facilitate transmetalation of the boron species, high yields and enantioselectivities were generally achieved. Moreover, the use of such tetravalent boron species offers some improvements compared to the use of boronic acids in term of stability and ease of purification.

Rhodium‐Catalyzed Formation of Stereocontrolled Trisubstituted Alkenes from Baylis–Hillman Adducts

Efficient and general conditions for the formation of stereodefined trisubstituted alkenes by using the rhodium-catalyzed reaction of unactivated Baylis-Hillman adducts with either organoboronic acids or potassium trifluoro(organo)borates are reported (see scheme).We report here efficient and general conditions for the formation of stereodefined trisubstituted alkenes using the rhodium-catalyzed reaction of unactivated Baylis-Hillman adducts with either organoboronic acids and potassium trifluoro(organo)borates. The use of the [{Rh(cod)OH}(2)] precursor gave very fast coupling reactions under low catalyst loading, very mild reaction conditions (from room temperature up to 50 degrees C) and without the need of additional phosphane ligands. Based on the new reaction conditions, the reaction, originally limited to Baylis-Hillman adducts derived from esters, could be extended to a large variety of Baylis-Hillman adducts, bearing either keto, cyano or amido functionalities. Moreover, the reaction of Baylis-Hillman adducts bearing esters functionality was improved and could be conducted at lower temperature using lower catalyst loading.

Access to Enantioenriched α-Amino Esters via Rhodium-Catalyzed 1,4-Addition/Enantioselective Protonation

Conjugate addition of potassium trifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected alpha-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol), an inexpensive and nontoxic phenol, afforded the highest asymmetric inductions. Organostannanes have also shown to participate in this reaction. By a fine-tuning of the ester moiety, and using Difluorophos as chiral ligand, increased levels of enantioselectivity, generally close to 95%, were achieved. Deuterium labeling experiments revealed, and DFT calculation supported, an unusual mechanism involving a hydride transfer from the amido substituent to the alpha carbon explaining the high levels of enantioselectivity attained in controlling this alpha chiral center.

Regio‐ and Stereoselective Palladium‐Pincer Complex Catalyzed Allylation of Sulfonylimines with Trifluoro(allyl)borates and Allylstannanes: A Combined Experimental and Theoretical Study

Regio- and stereoselective palladium-pincer complex catalyzed allylation of sulfonylimines has been performed by using substituted trifluoro(allyl)borates and trimethylallylstannanes. The reactions provide the corresponding branched allylic products with excellent regioselectivity. The stereoselectivity of these processes is very high when trifluoro(cinnamyl)borate and trimethyl cinnamyl stannane are employed as allylic precursors; however, the reaction with trifluoro(crotyl)borate results in poor stereoselectivity. The major diastereomer formed in these reactions was the syn isomer, while the (previously reported) reactions with aldehyde electrophiles afforded the anti products, indicating that the mechanism of the stereoselection is dependent on the applied electrophile. Therefore, we have studied the mechanistic aspects of the allylation reactions by experimental studies and DFT modeling. The experimental mechanistic studies have clearly shown that potassium trifluoro(allyl)borate undergoes transmetallation with palladium-pincer complex 1 a affording an eta(1)-allylpalladium-pincer complex (1 e). The mechanism of the transfer of the allyl moiety from palladium to the sulfonylimine substrate was studied by DFT calculations at the B3PW91/LANL2DZ+P level of theory. These calculations have shown that the electrophilic substitution of sulfonylimines proceeds in a one-step process with a relatively low activation energy. The topology of the potential energy surface in the vicinity of the transition-state structure proved to be rather complicated as nine different geometries with similar energies were located as first order saddle points. Our studies have also shown that the high stereoselectivity with cinnamyl metal reagents stems from steric interactions in the TS structure of the allylation reaction. In addition, these studies have revealed that the mechanism of the stereoselection in the allylation of aldehydes and sulfonylimines is fundamentally different.

Access to Stereodefined Trisubstituted Alkenes via Rhodium‐Catalyzed 1,4‐Addition of Potassium Trifluoro(organo)borates to Baylis—Hillman Adducts.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Access to Stereodefined Trisubstituted Alkenes via Rhodium‐Catalyzed 1,4‐Addition of Potassium Trifluoro(organo)‐ borates to Baylis–Hillman Adducts

AbstractIn the presence of a rhodium catalyst, unactivated Baylis–Hillman adducts reacted regioselectively with potassium trifluoro(organo)borates to afford stereodefined trisubstituted alkenes with good yields. This highly efficient reaction (aerobic conditions, low temperature, absence of added phosphane ligand) is believed to proceed via a 1,4‐addition/β‐hydroxy elimination mechanism.

Carbinol Derivatives via Rhodium‐Catalyzed Addition of Potassium Trifluoro(organo)borates to Aldehydes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Palladium Pincer Complex Catalyzed Substitution of Vinyl Cyclopropanes, Vinyl Aziridines, and Allyl Acetates with Tetrahydroxydiboron. An Efficient Route to Functionalized Allylboronic Acids and Potassium Trifluoro(allyl)borates.

Palladium-catalyzed boronation of vinyl cyclopropane, vinyl aziridine, and allyl acetate substrates could be accomplished using tetrahydroxydiboron reagent in the presence of SeCSe pincer complex catalyst 1a. These reactions result in allyl boronic acids, which were converted to synthetically useful trifluoro(allyl)borates or allyl boronates. The catalytic transformations proceed under mild and neutral conditions, and therefore many functionalities Br, COOEt, ArSO2(NH), OAc, and SiRMe2 are tolerated. The selectivity of the presented processes is very high, affording the linear products incorporating a trans double bond.

Potassium Trifluoro(organo)borates in Rhodium‐Catalyzed 1,4‐Additions to α,β‐Unsaturated Esters.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Palladium Pincer Complex Catalyzed Substitution of Vinyl Cyclopropanes, Vinyl Aziridines, and Allyl Acetates with Tetrahydroxydiboron. An Efficient Route to Functionalized Allylboronic Acids and Potassium Trifluoro(allyl)borates

Palladium-catalyzed boronation of vinyl cyclopropane, vinyl aziridine, and allyl acetate substrates could be accomplished using tetrahydroxydiboron reagent in the presence of SeCSe pincer complex catalyst 1a. These reactions result in allyl boronic acids, which were converted to synthetically useful trifluoro(allyl)borates or allyl boronates. The catalytic transformations proceed under mild and neutral conditions, and therefore many functionalities Br, COOEt, ArSO2(NH), OAc, and SiRMe2 are tolerated. The selectivity of the presented processes is very high, affording the linear products incorporating a trans double bond.

Palladium Pincer Complex Catalyzed Allylation of Tosylimines by Potassium Trifluoro(allyl)borates.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Potassium trifluoro(organo)borates in rhodium-catalyzed 1,4-additions to α,β-unsaturated esters

This letter describes an efficient and enantioselective conjugate addition of highly stable potassium trifluoro(organo)borates to α,β-unsaturated esters. This reaction, catalyzed by chiral rhodium(I) complexes, affords Michael adducts with high yields and enantiomeric excesses up to 96%.

Direct Access to Ketones from Aldehydes via Rhodium‐Catalyzed Cross‐Coupling Reaction with Potassium Trifluoro(organo)borates.

AbstractFor Abstract see ChemInform Abstract in Full Text.