The First High-yielding Benzyne Cyclisation Using a Phenolic Nucleophile: A New Route to Xanthenes
作者:David W. Knight、Paul B. Little
DOI:10.1055/s-1998-1878
日期:1998.10
Condensation of dianion 2 derived from aminobenzotriazole 1 with O-benzyl-salicylaldehydes 11 gives intermediate alcohols 12 in good yields. Double hydrogenolysis gives phenols 13 which, upon deprotection and benzyne generation using N-iodosuccinimide, undergo smooth cyclisation to give the iodo-xanthenes 14 in excellent overall yields.
The first efficient method for the intramolecular trapping of benzynes by phenols: a new approach to xanthenes
作者:David W. Knight、Paul B. Little
DOI:10.1039/b103834f
日期:——
-1H-benzotriazole and silyloxysalicylaldehydes 10 give excellent yields of the expected adducts 11. While attempts to remove the N-Boc function were unsuccessful, desilylation and hydrogenolysis delivered the hydroxybenzyl derivative 14 which could be efficiently deprotected to give the amine 15. This then underwent smooth decomposition to the benzyne 16, upon exposure to N-iodosuccinimide, and intramolecular