By double alkylation of chiral isoquinoline formamidines, a 71% yield of the bis-1,3(1-tetrahydroisoquinolinyl)propane was formed in >95% ee, Macrocyclization using 2-bromoacetyl bromide gave the [9]-ring diazaheterocycle (11) and the [18]-ring tetra-azaheterocycle (12) in 24 and 57% yields, respectively. After reduction of these lactams, the title compounds 13 and 15 were obtained. X-ray structures are presented for these novel chiral ring systems. (C) 1998 Elsevier Science Ltd. All rights reserved.
Recent progress using chiral formamidines in asymmetric syntheses
作者:A.I. Meyers
DOI:10.1016/s0040-4020(01)88523-9
日期:1992.3
The ability to generate a carbanion next to nitrogen in a chiral environment has led to a number of useful asymmetric routes to alkaloids and related substances. Mechanistic studies have been conducted to understand the nature of these alkylations.
MEYERS, A. I.;FUENTES, L. M.;KUBOTA, YOSHIKAZU, TETRAHEDRON, 1984, 40, N 8, 1361-1370
作者:MEYERS, A. I.、FUENTES, L. M.、KUBOTA, YOSHIKAZU
DOI:——
日期:——
Chiral formamidines. The mechanism of mono- and di-alkylation leading to chiral, non-racemic tetrahydroisoquinolines.
作者:A.I. Meyers、Joseph S. Warmus、Michael A. Gonzalez、Joseph Guiles、Atsushi Akahane
DOI:10.1016/0040-4039(91)80070-m
日期:1991.9
The effect on facial selectivity and degree of stereoselectivity by varying the size of the chiral auxillary allows a mechanism for alkylation to be presented.