Conjugated imines and iminium salts as versatile acceptors of nucleophiles
作者:Makoto Shimizu、Iwao Hachiya、Isao Mizota
DOI:10.1039/b814930e
日期:——
development of synthetic methodologies where nucleophilicaddition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilicaddition reactions with alpha,beta-unsaturated aldimines, addition reactions using alkynyl imines, "umpoled" reactions of alpha-imino esters, and the use of iminium salts as reactive electrophiles.
Stereoselective cycloaddition of 1-glucosyl-1,3-butadienes with tert-butyl 2H-azirine-3-carboxylate, glyoxylates and imines
作者:M.José Alves、I.G. Almeida、A. Gil Fortes、A.P. Freitas
DOI:10.1016/s0040-4039(03)01696-4
日期:2003.8
Glucosyl dienes 1 have been reacted with the achiral 2H-azirine 4 and with glyoxylates, forming fused structures of type 5 and disaccharide-like compounds 7 with good to excellent selectivity. Glucosyl dienes 1 participated as dienophiles in reactions with Schiffbasesderivedfromanilines forming isoquinolines 10 and 11. The diastereoselectivity of this reaction is poor.
Gold(<scp>i</scp>)-catalyzed formation of dihydroquinolines and indoles from N-aminophenyl propargyl malonates
作者:Colombe Gronnier、Yann Odabachian、Fabien Gagosz
DOI:10.1039/c0cc00033g
日期:——
The use of [XPhosAu(NCMe)]SbF(6) in nitromethane at 100 degrees C allows the rapid and efficient formation of variously substituted dihydroquinolines, which can be subsequently converted into indoles by a rare photochemical rearrangement.
Alkylation of iminomalonate with Grignard reagents followed by oxidation and allylation gave symmetrical quaternary α-amino diesters in good yields. Subsequent desymmetrization of a diol derivative from these products was conducted via asymmetric carbamylation catalyzed by Cu-Bnbox to give chiral quaternary aminodiol mono-carbamates.
Diethyl N-anisyliminomalonate has been found to be an excellent electrophilic amination reagent for Grignard reagents to give N-alkylated products in good yields, and subsequent air oxidation affords N-alkylanisidines. (C) 2001 Elsevier Science Ltd. All rights reserved.