33538-29-3Relevant academic research and scientific papers
Organo[2-(hydroxymethyl)phenyl]dimethylsilanes as mild and reproducible agents for rhodium-catalyzed 1,4-addition reactions
Nakao, Yoshiaki,Chen, Jinshui,Imanaka, Hidekazu,Hiyama, Tamejiro,Ichikawa, Yoshitaka,Duan, Wei-Liang,Shintani, Ryo,Hayashi, Tamio
, p. 9137 - 9143 (2008/02/09)
Stable and reusable tetraorganosilicon reagents, alkenyl-, aryl-, and silyl[2-(hydroxymethyl)phenyl]-dimethylsilanes, undergo 1,4-addition reactions to α,β-unsaturated carbonyl acceptors under mild rhodium-catalysis. The reaction tolerates a diverse range of functional groups and is applicable to gram-scale synthesis. Use of a chiral diene ligand allows the achievement of the corresponding enantioselective transformations using the tetraorganosilicon reagents, providing the silicon-based approach to optically active ketones and substituted piperidones that serve as synthetic intermediates of pharmaceuticals. A rhodium alkoxide species is suggested to be responsible for a transmetalation step on the basis of the observed kinetic resolution of a racemic chiral phenylsilane in the enantioselective 1,4-addition reaction under the rhodium-chiral diene catalysis.
Internal Thioaldehyde Trapping by Enes and Dienes
Vedejs, E.,Eberlein, T. H.,Wilde, R. G.
, p. 2220 - 2226 (2007/10/02)
Intermolecular ene insertion of photochemically generated thioaldehyde MeO2CCH=S with β-pinene occurs at room temperature to give the sulfide 2c.The internal ene insertion of thioaldehyde 6 affords a six-membered carbocycle 9 rather than the seven-membered sulfide 10 which would correspond to the regiochemistry of the intermolecular process (eq 5, 6).Likewise, internal Diels-Alder trapping occurs without a dominant role for the regiochemical preferences seen in intermolecular reactions.Desulfurization of typical internal adducts such as 25,26 or 29,30 affords 31 and33,34, respectively.
