Cascade Silylcarbocyclization of Enediynes, Triynes SiCaT , and Diynals

Cascade Silylcarbocyclization of Enediynes, Triynes (SiCaT), and Diynals 

The cascade silylcarbocyclization is applicable to diynals. For example, the reaction of undec-l,6-diyn-ll-al 72 with PhMe2SiH, catalyzed by Rh(acac)(CO)2 affords the corresponding silylated exo-silylmefhylene(hydroxy)bis(cyclopentylidene) 73 (Eq. 20) [48]. 

The reaction of enediyne 74 in which the olefin moiety is located as a part of the cyclo-hexenyl ring proceeds through a cascade SiCaC bicyclization process, followed by /9-hydride elimination, to give tricyclic exo-silylmethylene-bis(cyclopentylidene) 75 in good yield (Eq. 21) [48]. 

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