139007-44-6Relevant articles and documents
Light-Driven Vitamin B12-Catalysed Generation of Acyl Radicals from 2-S-Pyridyl Thioesters
Ociepa, Micha?,Baka, Oskar,Narodowiec, Jakub,Gryko, Dorota
supporting information, p. 3560 - 3565 (2017/10/24)
Acyl radicals are invaluable intermediates in organic synthesis, however their generation remains challenging. Herein, we present an unprecedented light-driven, cobalt-catalysed method for the generation of acyl radicals from readily available 2-S-pyridyl thioesters. The synthetic potential of this methodology was demonstrated in the Giese-type acylation of activated olefins in the presence of heptamethyl cobyrrinate. This vitamin B12 derivative proved to be the most efficient catalyst in the studied process. The developed method features broad substrate scope (38 examples), good functional group tolerance, and mild reaction conditions. Moreover, it is easily scalable (illustrated on a 20-fold scale-up procedure), enabling its preparative use. Mechanistic studies revealed that the reaction proceeds via a radical pathway with the key steps involving the formation of an acyl-vitamin B12 complex and subsequent photolysis of the Co?C bond. (Figure presented.).
MILD AND CONVENIENT ONE-POT SYNTHESIS OF β-LACTAMS BY CONDENSATION OF TITANIUM ENOLATES OF 2-PYRIDYLTHIOESTERS WITH IMINES
Cinquini, Mauro,Cozzi, Franco,Cozzi, Pier Giorgio,Consolandi, Emanuela
, p. 8767 - 8774 (2007/10/02)
Treatment of 2-pyridylthioesters with triethylamine in the presence of titanium tetrachloride affords titanium enolates that add to imines to give β-lactams in fair to excellent yields with moderate to good stereoselectivity.
