1608460-75-8Relevant academic research and scientific papers
Titanium-catalyzed reductive umpolung reactions with a metal-free terminal reducing agent
Frey, Georg,Hausmann, J. Niklas,Streuff, Jan
, p. 5693 - 5696 (2015)
A new method for titanium-catalyzed reductive umpolung reactions is reported that overcomes the traditional requirement for a stoichiometric metallic reductant. With N,N′-disilylated tetramethyldihydropyrazine as a potent organic reducing agent, reductive carbonyl-nitrile, enone-acrylonitrile and pinacol coupling reactions can be achieved in good yields and stereoselectivities. [Cp2TiI2] is a superior catalyst to [Cp2TiCl2], which is rationalized by a faster generation of the active catalyst [Cp2TiI]. A mechanism is proposed that is in agreement with the experimental results. Replacing zinc: A protocol for titanium(III)-catalyzed reductive umpolung reactions is presented that enables the title reactions in the presence of an N,N′-disilylated tetramethyldihydropyrazine as an organic sacrificial reducing agent. It is successfully applied to carbonyl-nitrile, enone-acrylonitrile and pinacol coupling reactions. A remarkable effect of the titanocene counterion renders titanocene diiodide a superior catalyst.
The cross-selective titanium(III)-catalysed acyloin reaction
Feurer, Markus,Frey, Georg,Luu, Hieu-Trinh,Kratzert, Daniel,Streuff, Jan
supporting information, p. 5370 - 5372 (2014/05/06)
A titanium(iii)-catalysed intermolecular reductive coupling of ketones or imines with nitriles is described, which gives direct access to α-hydroxylated and α-aminated ketones. This coupling reaction is cross-selective and a catalytic version of the classical acyloin condensation. A reaction mechanism that is supported by first DFT calculations is discussed. the Partner Organisations 2014.
