Alkali Metal-mediated Synthesis of 1- and 4-Substituted N-Alkyl-1,2,3,4-tetrahydro- isoquinolines
摘要:
Reductive cleavage by electron transfer from Li or K metal of 1-alkoxy-substituted N-alkyltetrahydroisoquinolines led to the formation of organometallic derivatives. Quenching of these intermediates with electrophilic reagents afforded 1- or 4-substituted N-alkyl-1,2,3,4-tetrahydroisoquinolines, depending upon the nature of the metal.
Activation of benzylic amines towards regioselective metallation by borane complex formation
作者:Mark R. Ebden、Nigel S. Simpkins、David N.A. Fox
DOI:10.1016/0040-4039(95)01797-l
日期:1995.11
Formation of borane complexes of N, N-dimethylbenzylamine 4 and N methyltetrahydroisoquinoline 1 facilitates regioselective metallation of these systems using BuLi, giving benzylic anions which react with a range of electrophiles.
The direct C-1 arylation of N-methyl-1,2,3,4-tetrahydroisoquinolines via coupling of alpha-amino carbanions derived from Lewis acid complexed tetrahydroisoquinolines and in situ generated arynes is described. This process provides an easy access to the title compounds and a new synthetic route to (+/-)-cryptostyline alkaloids.