作者:Emily R. T. Robinson、Charlene Fallan、Carmen Simal、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1039/c3sc50199j
日期:——
The asymmetric annulation of a range of α,β-unsaturated acyl ammonium intermediates, formed from isothiourea HBTM 2.1 and anhydrides with either 1,3-dicarbonyls, β-ketoesters or azaaryl ketones gives either functionalised esters (upon ring opening), dihydropyranones or dihydropyridones in good yields (up to 93%) and high enantioselectivity (up to 97% ee).
Non-bonding 1,5-S⋯O interactions govern chemo- and enantioselectivity in isothiourea-catalyzed annulations of benzazoles
作者:Emily R. T. Robinson、Daniel M. Walden、Charlene Fallan、Mark D. Greenhalgh、Paul Ha-Yeon Cheong、Andrew D. Smith
DOI:10.1039/c6sc00940a
日期:——
Isothiourea-catalyzed annulations of 2-acyl benzazoles and α,β-unsaturated acyl ammoniums are tuned to form lactams or lactones (up to 99% ee). Computations highlight the governing roles of S⋯O and CH⋯O interactions.