photoexcitation of enamines to trigger the formation of reactive carbon-centered radicals from iodosulfones, while the ground-state chiral enamines provide effective stereochemicalcontrol over the radical trapping process. The phenylsulfonyl moiety, acting as a redox auxiliary group, facilitates the generation of radicals. In addition, it can eventually be removed under mild reducing conditions to reveal methyl
Diastereoselective “contra-Michael" addition of(−)-sparteineorganolithiumcomplexes to secondary chiral cinnamyl amides
作者:Nathalie Bremand、Ilan Marek、Jean F. Normant
DOI:10.1016/s0040-4039(99)00495-5
日期:1999.4
"Contra-Michael" addition of (-)sparteine/organolithium reagents complexes to cinnamyl secondary amides derived From (R) or (S)-alpha-Methylbenzylamine occurs with marched or mismatched pairs, and allows an enantioselective access to 2-benzyl-amides,- acids, or- alcohols. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
Enantioselective Carbometalation of Cinnamyl Derivatives: New Access to Chiral Disubstituted Cyclopropanes— Configurational Stability of Benzylic Organozinc Halides
作者:Stephanie Norsikian、Ilan Marek、Sophie Klein、Jean F. Poisson、Jean F. Normant
β-alkyl substituted γ-lactones and whiskey lactone analogues were synthesized, and the odor properties were evaluated. During the preparation of the chiral intermediates, we found good reaction conditions for the highly enantioselective esterification of 3-arylmethyl-2-methyl-1-propanols to kinetically resolve them. The results of the olfactoryevaluations of the synthesized lactones revealed that the alkyl