Copper(I)-Catalyzed Substitution of Propargylic Carbonates with Diboron: Selective Synthesis of Multisubstituted Allenylboronates
摘要:
A versatile synthetic method for the preparation of the allenylboronates, Cu(I)-catalyzed reaction of propargylic carbonates with a diboron, is described. A Cu(O-t-Bu)-Xantphos catalyst system was effective for the preparation of various allenylboron compounds, allenylboronates with different substitution patterns, those with functional groups, and an axially chiral one. The Lewis acid promoted stereoselective addition to aldehydes leading to homopropargylic alcohols showed the usefulness of the new allenylboronates.
General and Functional Group-Tolerable Approach to Allenylsilanes by Rhodium-Catalyzed Coupling between Propargylic Carbonates and a Silylboronate
作者:Hirohisa Ohmiya、Hideto Ito、Masaya Sawamura
DOI:10.1021/ol902339a
日期:2009.12.17
The Rh-catalyzed coupling reaction between propargylic carbonates and a silylboronate afforded allenylsilanes with different substitution patterns in high yields. The reaction tolerates a variety of functional groups in propargylic carbonates. The reaction of an optically active propargylic carbonate proceeded with excellent chirality transfer with 1,3-anti stereochemistry to give an axially chiral
Palladium-Catalyzed Reaction of Propargylic Carbonates with Benzyne
作者:Shengming Ma、Shengjun Ni、Wei Shu
DOI:10.1055/s-0033-1339861
日期:——
Under the catalysis of palladium acetate, 1,2-allenyl-palladium formed from propargylic carbonates may react with two molecules of benzyne to afford phenanthrene derivatives by cyclization and beta-H elimination.