Employing TBN/TEMPO as the catalysts and oxygen as the oxidant, the biologically and pharmaceutically significant tetrahydro-β-carboline and β-carboline alkaloid scaffolds that used to be obtained by multi-step processes can now be selectively obtained in only one-step via direct aerobicoxidative Pictet–Spengler reactions of tryptamines with alcoholsundermildconditions, with water generated as
Cobalt–Rhodium Heterobimetallic Nanoparticle-Catalyzed N-Alkylation of Amines with Alcohols to Secondary and Tertiary Amines
作者:Hyunho Chung、Young Keun Chung
DOI:10.1021/acs.joc.8b01109
日期:2018.8.3
selectively catalyze both mono- and bis-N-alkylation through the coupling of simple alcohols with amines, yielding a range of secondary and tertiary amines in good to excellent isolated yields. The reaction can be applied to benzyl alcohol with optically active 1-phenylethan-1-amines, and secondary amines were isolated in quantitative yields with an excellent enantiomeric excess (ee > 94%). Selectivity
Synthesis of tetrahydro-β-carbolines via isomerization of N-allyltryptamines: a metal-catalyzed variation on the Pictet–Spengler theme
作者:Erhad Ascic、Casper L. Hansen、Sebastian T. Le Quement、Thomas E. Nielsen
DOI:10.1039/c2cc17704h
日期:——
An efficient and broadly applicable alternative to the classical Pictet-Spengler synthesis of tetrahydro-beta-carbolines is presented. The method relies on metal-catalyzedisomerization of allylic amines to form reactive iminium intermediates which can be trapped by a tethered indole nucleophile.