A Unified Approach to the Isomeric α-, β-, γ-, and δ-Carbolines via their 6,7,8,9-Tetrahydro Counterparts
作者:Qiao Yan、Emma Gin、Martin G. Banwell、Anthony C. Willis、Paul D. Carr
DOI:10.1021/acs.joc.7b00323
日期:2017.4.21
A cross-coupling/reductive cyclization protocol has been employed in a unified approach to all four carbolines. So, for example, the 2-nitropyridine 8, which is readily prepared through an efficient palladium-catalyzed Ullmann cross-coupling reaction, is reductively cyclized under conventional conditions to give 6,7,8,9-tetrahydro-alpha-carboline that is itself readily aromatized to give alpha-carboline (1).