Synthesis of Vinylogous β-Amino Esters fromN-(N,N-Dialkylaminoalkyl)benzotriazoles
摘要:
Treatment of N-(NN-dialkylaminoalkyl)benzotriazoles with 4-bromocrotonates in the presence of zinc provides a new route to 5(N,N-dialkylamino)-2-alkenoate esters. This is formally the result of they-addition of zinc dienolate reagents to iminium cations formed in situ by dissociation of the aminoalkylbenzotriazoles. When N-allyl protecting groups are incorporated into the benzotriazole substrate, deallylation of the tertiary allylamine products gives also a ready access to the corresponding secondary amines.
Synthesis of Vinylogous β-Amino Esters from<b><i>N</i></b>-(<b><i>N</i></b>,<b><i>N</i></b>-Dialkylaminoalkyl)benzotriazoles
作者:José M. Aurrecoechea、Alvaro Fernández、José M. Gorgojo、Rubén Suero
DOI:10.1081/scc-120016308
日期:2003.1.4
Treatment of N-(NN-dialkylaminoalkyl)benzotriazoles with 4-bromocrotonates in the presence of zinc provides a new route to 5(N,N-dialkylamino)-2-alkenoate esters. This is formally the result of they-addition of zinc dienolate reagents to iminium cations formed in situ by dissociation of the aminoalkylbenzotriazoles. When N-allyl protecting groups are incorporated into the benzotriazole substrate, deallylation of the tertiary allylamine products gives also a ready access to the corresponding secondary amines.
Synthesis of 2,4-, 3,4- and 2,3,4-substituted pyrrolidines by cyclization of neutral C-centered α-aminoalkyl radicals
作者:Fernando Bustos、José M Gorgojo、Rubén Suero、José M Aurrecoechea
DOI:10.1016/s0040-4020(02)00754-8
日期:2002.8
The effect of substitution at C-3 or C-4 of the 2-azahex-5-enyl chain has been studied in the SmI2-promoted cyclizations of neutral α-aminoalkyl radicals generated from N-(α-benzotriazolyl)alkenylamines. 2,4-, 3,4- and 2,3,4-substituted pyrrolidines are obtained in this manner in uniformly high yields but with stereoselectivities which depend markedly on the substitution pattern. Thus, a methyl substituent