Rhodium-Catalyzed Asymmetric Arylation/Defluorination of 1‑(Trifluoromethyl)alkenes Forming Enantioenriched 1,1-Difluoroalkenes

The reaction of 1-(trifluoromethyl)­alkenes (CF3CH=CHR) with arylboroxines (ArBO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral 1,1-difluoroalkenes (CF2=CHC*HArR) with high enantioselectivity (≥95% ee). The reaction is assumed to proceed through β-fluoride elimination of a β,β,β-trifluoroalkylrhodium intermediate that is generated by arylrhodation of the 1-(trifluoromethyl)­alkene

Rhodium-Catalyzed Asymmetric Arylation/Defluorination of 1‑(Trifluoromethyl)alkenes Forming Enantioenriched 1,1-Difluoroalkenes

The reaction of 1-(trifluoromethyl)­alkenes (CF₃CH=CHR) with arylboroxines (ArBO)₃ in the presence of a chiral diene-rhodium catalyst gave high yields of chiral 1,1-difluoroalkenes (CF₂=CHC*HArR) with high enantioselectivity (≥95% ee). The reaction is assumed to proceed through β-fluoride elimination of a β,β,β-trifluoroalkylrhodium intermediate that is generated by arylrhodation of the 1-(trifluoromethyl)­alkene

Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines

The reaction of racemic diarylmethylamines, (Ar¹Ar²CHNR₂), where Ar¹ is substituted with a 2-hydroxy group, with arylboroxines (Ar³BO)₃ in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar¹Ar²CH*Ar³) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through <i>o</i>-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents

Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines

The reaction of racemic diarylmethylamines, (Ar¹Ar²CHNR₂), where Ar¹ is substituted with a 2-hydroxy group, with arylboroxines (Ar³BO)₃ in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar¹Ar²CH*Ar³) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through <i>o</i>-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents

Stereoselective Synthesis of Tri- and Tetrasubstituted Allylsilanes via Copper-Catalyzed Decarboxylative Silylation of Vinylethylene Carbonates

Herein, a stereoselective copper-catalyzed decarboxylative silylation of readily available vinylethylene carbonates (VECs) with PhMe2Si-Bpin is reported, affording a wide range of tri- and tetrasubstituted allylsilanes in moderate to high yields with E-selectivity. This protocol was characterized by high stereoselectivity, broad substrate scope, operational simplicity, and mild reaction conditions, which were amenable to diverse derivatizations and gram-scale synthesis

Palladacycle-Catalyzed Olefinic C–P Cross-Coupling of Alkenylsulfonium Salts with Diarylphosphines to Access Alkenylphosphines

An efficient olefinic C–P cross-coupling of alkenylsulfonium salts with secondary diarylphosphines is reported. The use of a palladacycle enables the facile formation of a C–P bond at the alkenyl moiety of alkenylsulfonium salts tolerating a wide range of functional groups under mild conditions. This protocol provides an easy access to various alkenylphosphine products in good to high yields with high levels of stereoselectivity (E selectivity)

Rhodium-Catalyzed Highly Enantio- and Diastereoselective Alkenylation of β,γ-Unsaturated Butenolides via Dynamic Kinetic Resolution

A rhodium-catalyzed highly enantio- and diastereoselective alkenylation of β,γ-unsaturated butenolides is reported. The use of a chiral diene ligand, (S,S)-Ph-bod, enables the facile synthesis of chiral butyrolactones in high yields with extremely high enantioselectivities (>99% ee in all cases) and high diastereoselectivities (up to >20:1 dr). The key process of the reaction involves the isomerization of β,γ-unsaturated butenolides to racemic α,β-unsaturated butenolides and the subsequent dynamic kinetic resolution through ligand-controlled, enantioselective alkenylation with an alkenylrhodium species that is generated in situ via 1,4-rhodium migration

Asymmetric Synthesis of <i>P</i>‑Stereogenic Diarylphosphinites by Palladium-Catalyzed Enantioselective Addition of Diarylphosphines to Benzoquinones

The reaction of phenyl­(2,4,6-tri­methyl­phenyl)­phosphine with a substituted benzoquinone in the presence of a chiral phosphapalladacycle complex as a catalyst and triethylamine in chloroform at −45 °C proceeded in a new type of addition manner to give a high yield of a 4-hydroxyphenyl phenyl­(2,4,6-tri­methyl­phenyl)­phosphinite with 98% enantioselectivity, which is a versatile intermediate readily convertible into various phosphines and their derivatives with high enantiomeric purity

Asymmetric Synthesis of <i>P</i>‑Stereogenic Diarylphosphinites by Palladium-Catalyzed Enantioselective Addition of Diarylphosphines to Benzoquinones

The reaction of phenyl­(2,4,6-tri­methyl­phenyl)­phosphine with a substituted benzoquinone in the presence of a chiral phosphapalladacycle complex as a catalyst and triethylamine in chloroform at −45 °C proceeded in a new type of addition manner to give a high yield of a 4-hydroxyphenyl phenyl­(2,4,6-tri­methyl­phenyl)­phosphinite with 98% enantioselectivity, which is a versatile intermediate readily convertible into various phosphines and their derivatives with high enantiomeric purity

Dithiolation of Alkenyl Sulfonium Salts with Arylthiols to Access 1,2-Dithioalkanes

A dithiolation of alkenyl sulfonium salts with arylthiols is described, affording a series of 1,2-dithioalkanes in high yields. This protocol features mild and catalyst-free conditions and involves the formation of two C–S bonds sequentially via the regioselective addition of an arylthiol to the unsaturated CC bonds, followed by the attack of another arylthiol to form 1,2-dithioalkanes exclusively