A high temperature investigation using microwave synthesis for electronically and sterically disfavoured substrates of the Newman–Kwart rearrangement
作者:Jonathan D. Moseley、Philip Lenden
DOI:10.1016/j.tet.2007.02.101
日期:2007.5
Electronically deactivated and/or sterically hindered substrates undergo the Newman–Kwartrearrangement (NKR) at around 300 °C, beyond the range of most convenient and safe, small-scale laboratory equipment. We report here the convenient conversions of several difficult substrates using modern microwave technology, which has proven ideal for investigating this high temperature reaction in all but the most
Carbamates: A Directing Group for Selective C–H Amidation and Alkylation under Cp*Co(III) Catalysis
作者:Sourav Sekhar Bera、Modhu Sudan Maji
DOI:10.1021/acs.orglett.0c00589
日期:2020.4.3
The selective reactivity of carbamate and thiocarbamate toward alkylation and amidation is reported under stable, high-valent, cost-effective cobalt(III) catalysis. This method reveals the wide possibility of designing a different branch of synthetically challenging yet highly promising asymmetric catalysts based on BINOL and SPINOL scaffolds. Late-stage C-H functionalization of L-tyrosine and estrone was also achieved through this approach. The mechanistic study shows that a base-assisted internal electrophilic substitution mechanism is operative here.