Asymmetric Radical Addition of TEMPO to Titanium Enolates
作者:Phillip J. Mabe、Armen Zakarian
DOI:10.1021/ol403398u
日期:2014.1.17
A mild method for α-hydroxylation of N-acyl oxazolidinones by asymmetricradicaladdition of the 2,2,6,6-tetramethylpiperidine N-oxy (TEMPO) radical to titanium enolates was developed. The high diastereoselectivity and broad scope of the reaction show synthetic utility for the α-hydroxylation of substrates that are not tolerant to strongly basic conditions.
General and stereoselective aminoxylation of biradical titanium(<scp>iv</scp>) enolates with TEMPO: a detailed study on the effect of the chiral auxiliary
作者:Stuart C. D. Kennington、Alejandro Gómez-Palomino、Ernest Salomó、Pedro Romea、Fèlix Urpí、Mercè Font-Bardia
DOI:10.1039/c8ob01074a
日期:——
comprehensive analysis of the influence of the chiralauxiliary on the α-aminoxylation of titanium(IV) enolates with TEMPO indicated that (S) 4-tert-butyl-1-oxazolidine-2-thione is the most appropriate scaffold to provide a single diastereomer in high yields for a variety of substrates, which converts such a radical reaction into a highly chemo- and stereoselective oxidation.