Organocatalyzed asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactam
Highly efficient asymmetric vinylogous 1,6-Michael addition of α,β-unsaturated γ-butyrolactam to 3-methyl-4-nitro-5-alkenyl- isoxazoles and Michael addition to trichloromethyl ketones by using a chiral quinine-derived squaramide organocatalyst were described, giving products with high diastereo- and enantioselectivities (up to >25:1 dr and 96% ee).
Zhang, Jinlong,Liu, Xihong,Ma, Xiaojuan,Wang, Rui
supporting information
p. 9329 - 9331
(2013/10/01)
Recoverable phase-transfer catalysts with fluorinated anions: Generation and reactions of dichlorocarbene and CCl3 anion in the heterogeneous system KOH(s)/CHCl3/nBu4NPF6
Tetraalkylammonium salts bearing PF6- and BF 4- anions have been recognized as recoverable phase-transfer catalysts for the synthesis of 1,1-dichlorocyclopropane and α-(trichloromethyl) carbinol derivatives from alkenes or aldehydes in the heterogeneous system KOH(s)/CHCl3. The catalysts retained their catalytic activity over several reaction cycles. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Kryshtal, Galina V.,Zhdankina, Galina M.,Zlotin, Sergei G.
experimental part
p. 1777 - 1782
(2009/04/11)
Decomposition of sodium trichloroacetate in the presence of quaternary ammonium under microwave irradiation: A convenient one-pot synthesis of α-hydroxy acids in water
A good yielding phase-transfer-catalyzed procedure for one-pot preparation of α-hydroxy acids from carbonyl compounds and sodium trichloroacetate by in situ addition and hydrolysis under microwave irradiation is described. Decomposition of sodium trichloroacetate is strongly accelerated by the presence of quaternary ammonium. The reaction can be conducted in water. Copyright Taylor & Francis Group, LLC.
Yu, Haitao,Fang, Yun,Xia, Yongmei,Wu, Jing
p. 2421 - 2426
(2007/10/03)
General and Efficient Synthesis of 1,1,1-Trichloro-2-alkanols
1,1,1-Trichloroalkanols were readily obtained in good yields by reaction of trichloroacetic acid with aldehydes in hexamethylphosphoric triamide. 1,3-Dimethyl-2-imidazolidinone was found to be useful as an alternate solvent giving, however, lower yields.
NOVEL SELECTIVE SYNTHESIS OF α-CHLOROMETHYL, α,α-DICHLOROMETHYL, AND α,α,α-TRICHLOROMETHYL KETONES FROM ALDEHYDE UTILIZING ELECTROREDUCTION AS KEY REACTIONS
A variety of α-chloromethyl, α,α-dichloromethyl, and α,α,α-trichloromethyl ketones were synthesized from aldehyde utilizing cathodic reduction as key reactions.