Diethylphosphine oxide (DEPO): high-yielding and facile preparation of indolones in water.
[reaction: see text] Indolones are prepared in excellent yield at 80 degrees C in water by radical reaction (aryl radical formation, hydrogen atom abstraction, cyclization, and rearomatization) mediated by the reagent diethylphosphine oxide (DEPO). The reaction features V-501 as a water-soluble initiator; no other additives are needed. The process proceeds at a much lower temperature than is required for efficient reaction with toxic tributyltin hydride in benzene and permits significantly higher isolated yields than the corresponding reaction mediated by ethylpiperidine hypophosphite (EPHP).
Khan
Tanweer A
TA
Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK.
Tripoli
Régis
R
Crawford
James J
JJ
Martin
Concepcion G
CG
Murphy
John A
JA