The First Aryne Evolution from the Reactions of Selenonium Salts with Aryllithiums

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.