The asymmetric catalytic C À C bond formation by addition of an organozinc reagent to aldehydes for the synthesis of enantiomerically pure secondary alcohols as building blocks for bioactive compounds has been extensively studied, and numerous catalytic systems have been developed to yield excellent enantioselectivities.[1] Since tertiary alcohols appear in bioactive compounds, [2] the construction of chiral quaternary carbon centers is synthetically important owing to the inertness of ketones toward additions of carbon nucleophiles and less differentiation of the two groups attached to the carbonyl carbon atom. Despite efforts in recent years, only limited examples of catalytic asymmetric additions to ketones have been reported to give excellent stereoselectivities. Organozinc compounds have been used for asymmetric additions of alkyl compounds to ketones [3] or a-ketoesters [4] and for additions of vinyl, [5] alkynyl, [2c, 6] or aryl compounds [7] to ketones. For allyl addition reactions, the considerably toxic allyl tin compounds have been the commonly used reagents, [8] and in fewer cases, allyl silicon [2e, 9] or allyl boron compounds [10] have been used. In addition to these reagents, organoaluminum compounds are excellent nucleophiles for organic reactions [11] owing their high reactivities, a greater Lewis acidity of the aluminum center, and low toxicities. However, the use of organoaluminum compounds in asymmetric catalysis is rare. In the past few years, asymmetric catalytic alkylation, [12] allylation, [13] and alkynylation [14] reactions employing organoaluminum reagents have been established to achieve good to excellent enantioselectivities. Recently, we demonstrated that the novel [AlAr 3 (thf)] reagents are powerful aryl nucleophiles for additions to aldehydes catalyzed by the titanium catalyst of (R)-H 8 -binol (binol = 2,2'-dihydroxy-1,1'-binaphthyl) with the reactions complete in only 10 min. [15] In studies of asymmetric aryl additions to ketones, [7] only a few papers have been reported in just two catalytic systems. The first system is a zinc catalyst of (+)-daib (3-exo-(dimethylamino)isoborneol) with which direct additions of the ZnPh 2 reagent afford phenylation products.[7a] The second system is a series of titanium catalysts of disulfonamides [16] with which additions of ZnPh 2 or aryl zinc reagents furnish phenylation or arylation products. [7b-f] However, generation of aryl zinc reagents from excess ZnEt 2 and aryl boron compounds requires reaction conditions at elevated temperatures for 12-16 h. Furthermore, the arylation reactions have not reached a satisfactory level in yields and stereoselectivities.[7f] To extend applications of [AlAr 3 (thf)] reagents in catalysis, we report herein the first example of asymmetric aryl additions of organoaluminum reagents to ketones. The (S)-binol molecule was selected as the ligand since binol is a remarkable ligand applied to many varieties of asymmetric reactions [17] and since dititanium complexes of binol ligands with known structures [...