Grignard and organolithium reagents can be directly prepared from organohalides and are of great importance in organic synthesis. However, the high reactivity of these reagents makes it difficult to develop enantioselective catalysts for their nucleophilic addition to carbonyls to generate chiral alcohols. [1][2][3] In the past two decades, the use of organozinc reagents in asymmetric catalysis has been studied extensively. [4,5] Organozinc reagents are generally less reactive and more tolerant of functional groups than Grignard and organolithium reagents. These characteristics have allowed the rapid development of enantioselective catalysts for the asymmetric organozinc addition to carbonyls. Among these studies, several highly enantioselective catalysts were found for the asymmetric addition of vinylzinc compounds to carbonyls to generate chiral allylic alcohols. [6][7][8][9] In these reports, the vinylzinc reagents were prepared by using methods such as the hydrozirconation [6] or hydroboration [7] of alkynes with subsequent transmetallation, vinyl boronic acids or esters, [8] and the nickel-catalyzed addition of ZnMe 2 to alkynes.[9] The hydrozirconation and hydroboration of terminal alkynes generate alkenylzirconiums and alkenylboranes, respectively, which upon treatment with alkylzinc reagents can form the corresponding alkenylzinc reagents. These reagents in the presence of chiral ligands have been shown to be very useful for the asymmetric addition to carbonyls. [6, 7] However, the use of the hydrozirconation and hydroboration of terminal alkynes has limitations. For example, these methods cannot be applied to make cycloalkenylzinc reagents and only terminal alkynes are used in most cases. Preparation of vinylzinc reagents directly from vinyl halides would avoid these limitations. There is no report yet on the catalytic asymmetric reaction of carbonyl compounds with vinylzinc reagents that are prepared directly from vinyl halides without using the magnesium or lithium reagents, which are less tolerant of functional groups.[10] In 2004, Knochel and co-workers demonstrated that aryl iodides can be converted into arylzinc compounds by using ZniPr 2 , [11] but it was not known whether this strategy was applicable to vinyl iodides. Herein, we report the discovery of a highly enantioselective catalyst for the reaction of vinyl iodides with aldehydes through the direct conversion of vinyl iodides into vinylzinc reagents in the presence of ZnEt 2 . This method allows the synthesis of substituted and functionalized allylic alcohols with high enantiomeric purity under very mild reaction conditions. We first examined the reaction of a vinyl iodide, (E)-1-iodo-1-phenyl-1-pentene, with c-C 6 H 11 CHO in the presence of ZnEt 2 (Scheme 1). This led to the formation of the corresponding allylic alcohol in only a 17 % yield. The reactions of other vinyl iodides with aldehydes were also tested and these reactions normally gave low yields of product except for a few cases. These results indicate that the vinylzinc rea...