The First Aryne Evolution from the Reactions of Selenonium Salts with Aryllithiums
摘要:
The first example of the benzyne generation was found in the reactions of alkynylselenonium salt 1a with 1.0 equiv. of phenyllithium in THF at room temperature for 3 h. The formation of the aryne intermediate was confirmed in the reactions of alkynylselenonium salt 1b and tri-p-tolylselenonium salt 6b with tolyllithium, which gave a mixture of alkynylbiphenyl derivatives 18 and 19 in 19% yield (18:19=11:8) and a mixture of bitolyls 28 and 29 in 63% yield (28:29=2:1), respectively. The reaction mechanisms of these reactions are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.
Transition-Metal-Free Alkynylation of Aryl Chlorides
作者:Thanh Truong、Olafs Daugulis
DOI:10.1021/ol2014736
日期:2011.8.19
Two sets of conditions have been developed for a base-mediated, transition-metal-free alkynylation of aryl chlorides that proceeds via benzyne intermediates. The first set of conditions Involves the use of TMPLI base in a pentane/THF mixture at 25 degrees C. The second set Involves use of a metal alkoxide base in dioxane at elevated temperature. Reasonable functional group tolerance has been observed. Fluoro, trifluoromethyl, silyl, cyano, and alcohol functionalities are compatible with the reaction conditions.
Synthesis of Large Polycyclic Aromatic Hydrocarbons: Variation of Size and Periphery
series of polycyclicaromatichydrocarbons (PAHs) with different peripheries was synthesized via oxidative cyclodehydrogenation of suitable oligophenylene precursors under mild conditions. Such large PAHs are considered to be two-dimensional graphite sections whose electronic properties are expected to converge to those of macroscopic graphite. The synthetic buildup of the oligophenylene frameworks
The first example of the benzyne generation was found in the reactions of alkynylselenonium salt 1a with 1.0 equiv. of phenyllithium in THF at room temperature for 3 h. The formation of the aryne intermediate was confirmed in the reactions of alkynylselenonium salt 1b and tri-p-tolylselenonium salt 6b with tolyllithium, which gave a mixture of alkynylbiphenyl derivatives 18 and 19 in 19% yield (18:19=11:8) and a mixture of bitolyls 28 and 29 in 63% yield (28:29=2:1), respectively. The reaction mechanisms of these reactions are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.