Open AccessLewis Acid–Water/Alcohol Complexes as Hydrogen Atom Donors in Radical Reactions
Author(s) -
Guillaume Povie,
Philippe Renaud
Publication year - 2013
Publication title -
chimia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.387
H-Index - 55
eISSN - 2673-2424
pISSN - 0009-4293
DOI - 10.2533/chimia.2013.250
Subject(s) - chemistry , hydrogen atom , lewis acids and bases , radical , alcohol , hydrogen , boron , hydrogen bond , photochemistry , reagent , titanium , medicinal chemistry , molecule , organic chemistry , catalysis , group (periodic table)
Water or low molecular weight alcohols are, due to their availability, low price and low toxicity ideal reagents for organic synthesis. Recently, it was reported that, despite the very strong BDE of the O–H bond, they can be used as hydrogen atom donors in place of expensive and/or toxic group 14 metal hydrides when boron and titanium(III) Lewis acids are present. This finding represents a considerable innovation and uncovers a new perspective on the paradigm of hydrogen atom transfers to radicals. We discuss here the influence of complex formation and other association processes on the efficacy of the hydrogen transfer step. A delicate balance between activation by complex formation and deactivation by further hydrogen bonding is operative.