Regioselective alkylation reactions of 2,4-diphenyl-3H-1-benzazepine give either 3-alkyl-3H-1-benzazepines or 1-alkyl-1H-1-benzazepines
作者:Allen Ko、Aaron Lam、Jeffrey Li、Edyta M. Greer、David J. Szalda、Sasan Karimi、Gopal Subramaniam、Keith Ramig
DOI:10.1016/j.tetlet.2014.05.128
日期:2014.7
2,4-Diphenyl-3H-1-benzazepine is deprotonated with either LDA or KHMDS. The resulting anion is alkylated with alkyl halides or MeOTs, giving either products of alkylation at C3, or at N, or a mixture of both. The regioselectivity depends on the base, presence of the complexing agent HMPA, and the leaving group of the allcylating agent. Using Mel as alkylating agent gives exclusively the C3-methylated product, while using MeOTs gives exclusively the N-methylated product. The N-allcylated products show evidence of stereodynamic behavior in their NMR spectra. (C) 2014 Elsevier Ltd. All rights reserved.