A regioselective intramolecular cyclization/halogenation reaction of N-alkoxy-o-alkynylbenzamides with CuCl2/NCS was developed. The corresponding 3-(chloromethylene)isobenzofuran-1-ones were exclusively obtained via 5-exo-dig cyclization in moderate to excellent yields within 0.5-1 h. This approach has been successfully used to synthesize a biaryl compound by the Suzuki-Miyaura reaction.
Oxyanion-Accelerated C<sup>2</sup>−C<sup>6</sup> Cyclization of Benzannulated Enyne-allenes
作者:Steven R. Brunette、Mark A. Lipton
DOI:10.1021/jo991876v
日期:2000.8.1
The cyclization of oxyanion-substituted, benzannulated enyne-allenes was found to proceed rapidly and efficiently at room temperature, producing substituted indanones and fluorenones through a C2-C6 cyclization pathway. These reactions bear close resemblance to thermal C2-C6 cyclizations of enyne-allenes previously reported by Schmittel and others, though the oxyanion-substituted cases cyclize far
A regioselective intramolecular cyclization/halogenation reaction of N-alkoxy-o-alkynylbenzamides with CuCl2/NCS was developed. The corresponding 3-(chloromethylene)isobenzofuran-1-ones were exclusively obtained via 5-exo-dig cyclization in moderate to excellent yields within 0.5-1 h. This approach has been successfully used to synthesize a biaryl compound by the Suzuki-Miyaura reaction.