Tosvinyl and Besvinyl as Protecting Groups of Imides, Azinones, Nucleosides, Sultams, and Lactams. Catalytic Conjugate Additions to Tosylacetylene
作者:Elena Petit、Lluís Bosch、Joan Font、Laura Mola、Anna M. Costa、Jaume Vilarrasa
DOI:10.1021/jo501647w
日期:2014.9.19
The use of the 2-(4-methylphenylsulfonyl)ethenyl (tosvinyl, Tsv) group for the protection of the NH group of a series of imides, azinones (including AZT), inosines, and cyclic sulfonamides has been examined. The Tsv-protected derivatives are obtained in excellent yields by conjugate addition to tosylacetylene (ethynyl p-tolyl sulfone). The stereochemistry of the double bond can be controlled at will:
已经研究了2-(4-甲基苯基磺酰基)乙烯基(甲苯磺酰基,Tsv)用于保护一系列酰亚胺,叠氮基(包括AZT),肌苷和环状磺酰胺的NH基的用途。通过共轭添加到甲苯磺酰基乙炔(乙炔基对甲苯砜)中,Tsv保护的衍生物以优异的收率获得。可以任意控制双键的立体化学:仅用1 mol%的Et 3 N或催化量的NaH,几乎仅生成Z立体异构体,而使用化学计量的DMAP获得E异构体。通过与(Z)-或(E)-双(苯磺酰基)乙烯。对于内酰胺和恶唑烷酮,最后一种方法要好得多。Tsv和Bsv基团在非亲核碱和酸的存在下是稳定的。通过使用吡咯烷或十二烷硫醇钠作为亲核试剂的共轭加成-消除机制可以高效地去除它们。