Rhodium-catalyzed [2+2+2]cycloaddition of 1,6-diynes with isothiocyanates and carbon disulfide

[GRAPHICS] A neutral rhodium(I)/BINAP complex effectively catalyzed a [2+2+2] cycloaddition of 1,6-diynes with isothiocyanates to give bicyclic thiopyranimines in 59-98% isolated yield. The reaction with carbon disulfide also proceeded to give bicyclic dithiopyrones in 74-85% isolated yield.