Enynes, hydrosilation

Hydrosilation of conjugated enynes with HSiCl3 in the presence of a chiral palladium catalyst provides a route to enantioenriched allenyltrichlorosilanes [55]. A bulkyl alkynyl substituent such as tBu is most effective in directing facial and regios-electivity (Table 9.31). Two chiral ferrocenyl ligands, (S)-(R)-PPFOMe and (S)-(R)-bis-... 

The hydrosilation of l,4-bis(trimethylsilyl)-l,3-butadiyne gives either enynes as the product of monohydrosi-lation or allenes as deriving from di-hydrosilation (equation 15). ... 

Co2Rh2(CO)i2] and [Co3Rh(CO)i2] catalyze the hydrosilation of isoprene, cyclohexanone, cyclohexenone, and 1-alkynes, the regioseleetive inter- or intramolecular (Eq. 5) silylformylation of alkynes and 1-alkynals, and the silylcarbo-cyclization of enynes, diynes, and alkynals. These synthetically important reactions have been reviewed recently. 

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