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
Aryl Aldehydes as Traceless Dielectrophiles in Bifunctional Titanocene-Catalyzed Propargylic C–X Activations
作者:Catherine A. Campos、Joseph B. Gianino、David M. Pinkerton、Brandon L. Ashfeld
DOI:10.1021/ol202401n
日期:2011.10.21
directly from aromatic aldehydes is described. The starting aldehyde behaves as a traceless functionality in the formation of multiple carbon–carbon bonds through consecutive carbon–heteroatom bond activations. The sequential addition of a metal acetylide and a second carbonnucleophile to the dielectrophilic aldehyde enables the construction of symmetrical and unsymmetrical 1,4-diynes in good yields