Stable gold(III) catalysts by oxidative addition of a carbon–carbon bond
作者:Chung-Yeh Wu、Takahiro Horibe、Christian Borch Jacobsen、F. Dean Toste
DOI:10.1038/nature14104
日期:2015.1
Here we report a carbon–carbon bond cleavage at ambient conditions by a Au(i) complex that generates a stable Au(iii) cationic complex. In contrast to the well-established soft and carbophilic Au(i) catalyst, this Au(iii) complex exhibits hard, oxophilic Lewis acidity. For example, we observed catalytic activation of α,β-unsaturated aldehydes towards selective conjugate additions as well as activation
2-alkylphenyl bromides with biphenylene has been developed. The reactions formed eight-memberedcarbocycles through C(sp3)–H activation and the formation of two C–C bonds, and the chiral products were obtained with excellent diastereoselectivity. The reaction provides a new strategy for the construction of eight-memberedcarbocycles, and the products represent a novel type of chiral scaffold.
Biphenylenes. Part XIV. Synthesis of 1- and 2-phenyl-, 2,7-dimethyl-, and 2,3,6,7-tetramethyl-biphenylene
作者:P. R. Constantine、G. E. Hall、Charles R. Harrison、J. F. W. McOmie、R. J. G. Searle
DOI:10.1039/j39660001767
日期:——
1- and 2-Phenylbiphenylene have been made from 1- and 2-lithiobiphenylene, respectively, by treatment with cyclohexanone followed by dehydration and dehydrogenation. 2-Phenylbiphenylene has also been made by pyrolysis of 4- and 5-phenyl-biphenylene-2,2′-iodonium iodide with cuprous oxide.
The ring expansion reaction of ethyl cyclopropylideneacetate (1) with benzosilacyclobutenes proceeded smoothly in the presence of Ni(cod)(2)-TOPP (tribiphenyl-2-yl phosphite) to give benzosilacycloheptenes in good yields. This formal sigma bond metathesis reaction proceeded in a selective manner. The Ni-catalyzed reaction of 1 with biphenylenes was also examined. (C) 2010 Elsevier Ltd. All rights reserved.