Catalytic Enantioselective Conjugate Addition of Nitromethane to α′-Hydroxy Enones as Surrogates of α,β-Unsaturated Carboxylic Acids and Aldehydes
作者:Claudio Palomo、Raquel Pazos、Mikel Oiarbide、Jesús M. García
DOI:10.1002/adsc.200606076
日期:2006.7
No base is required for the Mg(II)-catalyzed conjugate addition of nitromethane to α′-hydroxy enones in the presence of molecular sieves. Good enantioselectivities are attained using 3 or 4 Å MS and about 10 mol % of Mg(OTf)2-chiral bisoxazoline complexes. Elaboration of the adducts through oxidative cleavage of the ketol moiety provides an entry to enantioenriched γ-nitro carboxylic acids, while a
Reaction of dithio-substituted cinnamyllithium with carbonyl compounds: a test of the HSAB principle
作者:Jim-Min Fang、Ming-Yi Chen、Wen-Jin Yang
DOI:10.1016/s0040-4039(00)82231-5
日期:1988.1
By mediation of BF3.Et2O, dithio-substituted cinnamyllithium 2 reacted predominantly at the α-site with carbonylcompounds. No selectivity was found when the reaction was performed in the absence of BF3.Et2O.