23727-04-0Relevant articles and documents
Free-radical hydroxylation reactions of alkylboronates
Cadot, Christine,Dalko, Peter I.,Cossy, Janine,Ollivier, Cyril,Chuard, Rachel,Renaud, Philippe
, p. 7193 - 7202 (2002)
The radical hydroxylation of B-alkylcatecholboranes, easily prepared by hydroboration of olefins, has been investigated. When molecular oxygen was used as oxidizing agent, the corresponding alcohols were obtained directly without alkaline treatment. The presence of Lewis base additives such as Et3N or DABCO has a benefic effect on the selectivity and yield. Alternatively, 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) reacts cleanly with B-alkylcatecholboranes to afford alkyl radicals that can be trapped by a second equivalent of TEMPO to give alkoxyamines. Reduction of the alkoxyamines with zinc in acetic acid affords the desired alcohols. The whole procedure is particularly mild and does not require any basic condition. The two approaches presented in this paper are valuable and represent mild alternatives to the classical alkaline oxidation of organoboranes to alcohols.
TEMPO-induced generation of alkyl radicals from B-alkylcatecholboranes
Ollivier, Cyril,Chuard, Rachel,Renaud, Philippe
, p. 807 - 809 (1999)
B-alkylcatecholboranes react efficiently with 2,2,6,6- tetramethylpiperidine-N-oxyl (TEMPO) to give alkyl radicals. In the presence of an excess of TEMPO, the generated radicals are efficiently convened to alkoxyamine derivatives.
A method for the net contra-thermodynamic isomerization of cyclic trisubstituted alkenes
Guignard, Raphael F.,Petit, Laurent,Zard, Samir Z.
, p. 4178 - 4181 (2013/09/12)
A simple sequence for the net contra-thermodynamic isomerization of cyclic trisubstituted alkenes is reported consisting of a radical addition of p-chlorothiophenol, followed by oxidation to the sulfoxide and thermal syn-elimination to give the least substituted isomeric cycloalkene.
