Generation of Cations from Alkoxides: Allylation of Propargyl Alcohols
摘要:
The reaction of alkoxides with boron trichloride results in the generation of cations in the absence of Brønsted acids. The absence of a Brønsted acid can make a difference in subsequent transformations such as allylation reactions.
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