Titanocene-Catalyzed Multicomponent Coupling Approach to Diarylethynyl Methanes
作者:Joseph B. Gianino、Brandon L. Ashfeld
DOI:10.1021/ja308891e
日期:2012.11.7
A titanocene-catalyzed multicomponent coupling to provide diarylethynyl methanes is described. By combining the multifunctionality of Cp2TiCl2 with the traceless dielectrophilicity of aryl aldehydes, all-carbon tertiary centers are obtained in 55-99% yield.
Redox and Lewis Acid Relay Catalysis: A Titanocene/Zinc Catalytic Platform in the Development of Multicomponent Coupling Reactions
作者:Joseph B. Gianino、Catherine A. Campos、Antonio J. Lepore、David M. Pinkerton、Brandon L. Ashfeld
DOI:10.1021/jo501890z
日期:2014.12.19
A titanocene-catalyzed multicomponent coupling is described herein. Using catalytic titanocene, phosphine, and zinc dust, zinc acetylides can be generated from the corresponding iodoalkynes to affect sequential nucleophilic additions to aromatic aldehydes. The intermediate propargylic alkoxides are trapped in situ with acetic anhydride, which are susceptible to a second nucleophilic displacement upon