Palladium complex (A)-catalyzed dimerization-hydrosilylation of 1-alkynes, which has previously been reported, can not be applied effectively to the intramolecular version of a,walkanediynes, while a cationic palladium complex (B) is a very effective catalyst for cyclization-hydrosilylation of functionalized a,w-diynes to give (Z)-1-methylene-2-silylmethylenecycloalkane derivatives, with 5-, 6-, and 7-membered ring, in good to moderate yields.

Organo-silicon compoundsOrgano-silicon compounds S 0060 Cationic Palladium Complex Catalyzed Cyclization-Hydrosilylation of 1,6-Heptadiyne and Its Homologues. -A cationic Pd-complex is described as an efficient catalyst for the title reaction. -(UNO, T.; WAKAYANAGI, S.; SONODA, Y.; YAMAMOTO*, K.; Synlett 2003, 13, 1997-2000; Dep. Mater. Sci. Eng., Sci. Univ. Tokyo, Onoda, Yamaguchi 756, Japan; Eng.) -Mais 08-169