3899-18-1Relevant articles and documents
Homocoupling versus reduction of radicals: An experimental and theoretical study of Ti(iii)-mediated deoxygenation of activated alcohols
Prieto, Consuelo,González Delgado, José A.,Arteaga, Jesús F.,Jaraíz, Martín,López-Pérez, José L.,Barrero, Alejandro F.
, p. 3462 - 3469 (2015/03/18)
A detailed experimental and theoretical study corroborates that the reductive deoxygenation of activated (allylic or benzylic) alcohols with excess Ti(iii) proceeds via an allyl(benzyl)-radical and allyl(benzyl)-Ti, which is protonated, regioselectively in the case of allylic derivatives. The H atom of the newly formed C-H bond in the product originates from the -OH group of the starting material. The deoxygenation of lithium alkoxides or alcohols by using 1.0 mol of Ti(iii) leads to the corresponding dimerization products in good yields. An excellent agreement with the experimental data was obtained by using a reaction kinetics simulator to discriminate between competing reactions.
Electro-organic Reactions. Part 16. The Preparative-scale Cathodic Hydrogenolysis and Coupling of Benzyl-, Allyl-, Cinnamyl-, and Polyenylphosphonium salts
Utley, James H. P.,Webber, Andrew
, p. 1154 - 1160 (2007/10/02)
An investigation of the cathodic reduction of benzyltriphenylphosphonium nitrate confirms that optimum yields of the product of coupling (bibenzyl) are formed at an aluminium cathode using high current densities and in dimethylformamide or hexamethylphosphoramide solution.The cathodic reduction of allylphosphonium salts gives mainly cleavage; e.g. α-farnesene (5) is obtained in 32percent yield from the corresponding farnesylphosphonium salt.Moderately efficient coupling (ca. 30percent) is observed for the electro-reduction of trans-cinnamyltriphenylphosphonium nitrate (6) and a C15 polyenylphosphonium salt (7).The products of coupling have been fully characterised; the relative proportions of positional isomers are apparently dictated by steric factors.
