On the Regioselectivity of the Nickel-Catalyzed Insertion of Alkynes into the Carbon–Carbon Bond of Oxetan-3-one

The study of the regioselectivity of insertion of unsymmetrical alkynes into the carbon–carbon bond of oxetan-3-one in the presence of a nickel catalyst has revealed a strong directing effect of a 2-thienyl substituent. This effect is larger than those of 2-vinylbenzene, trimethylsilyl, aryl, or 3-thienyl groups.