Aryllithiums with Increasing Steric Crowding and Lipophilicity Prepared from Chlorides in Diethyl Ether. The First Directly Prepared Room-Temperature-Stable Dilithioarenes
作者:Constantinos G. Screttas、Barry R. Steele、Maria Micha-Screttas、Georgios A. Heropoulos
DOI:10.1021/ol302672n
日期:2012.11.16
A convenient procedure has been developed for the preparation of synthetically useful, room-temperature-stable aryllithiums starting from aryl chlorides and lithium metal. The method provides a route to aryllithiums which have previously not been accessible cleanly or could only be prepared by using more expensive starting materials.
Platinum Oxide Catalyzed Hydrosilylation of Unsymmetrical Internal Aryl Alkynes under Ortho-Substituent Regiocontrol
[GRAPHICS]PtO2- and H2PtCl6-catalyzed hydrosilylation of internal aryl alkynes having a para or an ortho substituent with triethylsilane are discussed and compared. The regioselectivity of the H-Si bond addition was found to be controlled by the ortho substituent rather than the nature of the platinum catalyst. Arylallcynes with an ortho substituent, regardless of its electronic nature, directed the silyl substituent mainly to the a-position. PtO2 proved to be a versatile and powerful catalyst compared to H2PtCl6 since it prevents the alkyne reduction.
Teitei, Tsutomu, Agricultural and Biological Chemistry, 1983, vol. 47, # 7, p. 1461 - 1466