Catalytic asymmetric allylation of aldehydes with allylic trimethoxysilanes was achieved with the p-Tol-BINAP small middle dotAgF complex as catalyst [Eq. (a); p-Tol-BINAP=2,2'-bis(di-p-tolylphosphanyl)-1,1'-binaphthyl)]. High anti and enantioselectivities were obtained in the reaction with crotyltrimethoxysilane, irrespective of the configuration at the double bond.

Catalytic asymmetric Mukaiyama-type aldol reaction using trimethoxysilyl enol ethers was achieved using 2,2′-bis(di-p-tolylphosphino)-1,1′-binaphthyl (p-Tol-BINAP)·AgF complex as a catalyst. The chiral silver(I) catalyst was easily generated by mixing p-Tol-BINAP and silver(I) fluoride in MeOH at room temperature. High syn- and enantioselectivities were obtained from both the E- and Z-silyl enol ethers. Use of a 1 : 1 mixture of MeOH and acetone as a solvent in the reaction of cyclohexanone-derived trimethoxysilyl enol ethers resulted in higher enantioselectivity.

New catalytic asymmetric Mukaiyama-type aldol reaction using trimethoxysilyl enol ethers was achieved using p-Tol-BINAP·AgF complex as a catalyst. High syn-and enantioselectivities were obtained both from the E-and Z-silyl enol ethers.The Mukaiyama aldol reaction is a favorite method for the synthesis of b-hydroxy carbonyl compounds. 1 Although a variety of chiral Lewis acid catalysts have been developed for the asymmetric reaction of trialkylsilyl enol ethers or ketene trialkylsilyl acetals with carbonyl compounds, 1,2 most of those used are main-group metal (B, Zn, Sn, etc.) compounds or first row-transition metal (Ti, Cu, etc.) compounds, and the use of second or third row-transition metal compounds such as silver catalysts has received little attention. 3,4 In a previous paper, 5 we showed a new catalytic asymmetric Sakurai-Hosomi allylation reaction using the p-Tol-BINAP·AgF complex. We describe here a new example of catalytic asymmetric aldol condensation using trimethoxysilyl enol ethers and p-Tol-BINAP·AgF complex (eq 1). 6

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