Allenylsilanes are useful intermediates in organic synthesis, reacting with a variety of electrophiles in a regiospecific manner. 1 For example, the reaction with carbonyl compounds provides a selective route to homopropargylic alcohols. Recently, considerable attention has been paid to the preparation of axially chiral allenylsilanes and their use for the asymmetric synthesis of homopropargylic alcohols. 2 However, to our best knowledge, only one report has appeared on the catalytic asymmetric synthesis of allenylsilanes, which was attained by rhodium-catalyzed asymmetric double hydrosilylation of a 1,3-diyne, giving a 1,3-bis-(silyl)-1,2-propadiene derivative of 22% ee. 3 On the other hand, we have continued our studies on the palladium-catalyzed asymmetric hydrosilylation of olefins. 4 High enantioselectivity has been reported for various types of olefins including alkylsubstituted terminal alkenes, cyclic alkenes, styrene derivatives, and 1,3-dienes by use of axially chiral monodentate phosphine ligands. 5 The palladium-catalyzed hydrosilylation of 1,3-dienes with trichlorosilane is unique in that exclusive 1,4-addition takes place, giving allylsilanes with perfect selectivity, probably due to a contribution of π-allylpalladium intermediates. 6 We anticipated that a proper design of the catalytic reaction system would realize the regio-and enantioselective 1,4-addition to 1,3-enynes, giving axially chiral allenylsilanes. Here we report our results that allenylsilanes of up to 90% ee are obtained by the catalytic asymmetric hydrosilylation of 1,3-enynes.We examined 1-buten-3-ynes containing various types of substituents at 4-position for the palladium-catalyzed hydrosilylation with trichlorosilane and found that the selectivity in giving allenylsilane is strongly dependent on the steric bulkiness of the substituent. 7 The selectivity is high for 1-buten-3-ynes containing sterically bulky groups such as tert-butyl, mesityl, or tertbutyldimethylsilyl, while it is low for those containing less bulky groups (Scheme 1). 8 In the reaction of 5,5-dimethyl-1-hexen-3-yne (1a, R ) tert-Bu in RCtCsCHdCH 2 ), we looked for the chiral phosphine ligand whose palladium complex catalyzes the hydrosilylation, forming allenylsilane in high yield with high enantioselectivity. Chelating bisphosphines such as binap cannot be used because the hydrosilylation is very slow, as has been usually observed in the palladium-catalyzed hydrosilylation with trichlorosilane. 5 The chiral monophosphines (MOPs) whose chirality is due to the binaphthyl axial chirality were not as effective for the present 1,3-enyne substrates as for other types of olefinic substrates. 5 The enantioselectivity was 27% and 18% with MeO-MOP 9 and Ar-MOP, 6,10 respectively. Much higher enantioselectivity was observed in the reaction with chiral ferrocenylmonophosphines based on the ferrocene planar chirality. 11,12 Of those reported so far, (S)-(R)-PPFOMe 12 showed the highest enantioselectivity. Thus, a mixture of 1a (2.0 mmol), trichlorosilane (4.4 mmol), and 1.0...