Regioselective conjugate 1,4-trifluoromethylation of alpha,beta-unsaturated ketones by the use of shelf-stable electrophilic trifluoromethylating reagents, S-(trifluoromethyl)diphenylsulfonium salts and copper under mild conditions is described. A wide range of acyclic aryl-aryl-enones and aryl-alkyl-enones were converted into beta-trifluoromethylated ketones in low to moderate yields.
Base-Catalyzed Stereospecific Isomerization of Electron-Deficient Allylic Alcohols and Ethers through Ion-Pairing
作者:Samuel Martinez-Erro、Amparo Sanz-Marco、Antonio Bermejo Gómez、Ana Vázquez-Romero、Mårten S. G. Ahlquist、Belén Martín-Matute
DOI:10.1021/jacs.6b08350
日期:2016.10.12
between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylicethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.
A Novel Synthesis of Trifluoromethylated Multi-Substituted Alkenes via Regio- and Stereoselective Heck Reaction of (<i>E</i>)-4,4,4-Trifluoro-1-phenyl-2-buten-1-one
Treatment of (E)-4,4,4-trifluoro-1-phenyl-2-buten-1-one with various aryldiazonium salts in the presence of a palladium catalyst led to a smooth Heck reaction, furnishing α-arylated adducts in good yields.
Unexpected high regiocontrol in Heck reaction of fluorine-containing electron-deficient olefins—Highly regio- and stereoselective synthesis of β-fluoroalkyl-α-aryl-α,β-unsaturated ketones
Treatment of (E)-4,4,4-trifluoro-1-aryl-2-buten-1-one with various aryldiazonium salts in the presence of palladium catalyst gave the corresponding α-arylated Heck adducts with high regio- and stereoselectivity in good to high yields.
Rhodium(<scp>i</scp>)-catalyzed 1,4-conjugate arylation toward β-fluoroalkylated electron-deficient alkenes: a new entry to a construction of a tertiary carbon center possessing a fluoroalkyl group
Treatment of β-fluoroalkylated-α,β-unsaturated ketones with 1.2 equiv. of various arylboronic acids in the presence of 5 mol% of [Rh(COD)2]BF4 and 6 mol% of (S)-BINAP in toluene/H2O (v/v = 4/1) at the reflux temperature for 3 h gave the corresponding Michael adducts in high yields with over 90% enantioselectivity. Though other electron-deficient alkenes, such as vinylsulfone and vinylphosphonate, were found to be much less reactive in the rhodium-catalyzed conjugate addition with arylboronic acids, the reaction of various arylstannanes toward such electron-deficient alkenes took place very smoothly to afford the corresponding adducts in high yields.