The transition metal-catalyzed transfer of silicon nucleophiles [1] onto various electrophiles, has recently gained considerable attention, [2] owing to the development of readily available silicon pro-nucleophiles. In particular, the reagent developed by the Suginome group, which possesses a SiÀB linkage has become one of the major sources of nucleophilic silicon. [1a] This new method is particularly attractive, as it provides a facile access to metal-silicon reagents that render the use of any activating agents unnecessary.These metal-silicon intermediates allow the catalytic transfer of a silicon nucleophile onto various electrophiles; our interest lies in the addition of such species to aldehydes, thus generating a-hydroxysilanes. This type of C À Si bond formation as well as the hydroxy group is of crucial importance in organic synthesis. Moreover, a stereogenic center is formed in this process, thus generating possible opportunities for asymmetric catalysis.Optically active a-hydroxysilanes are a class of chiral organometallic compounds that contain a functional group. These molecules and their derivatives have been used for stereocontrolled C À C bond formation and rearrangements, which resulted in a wide variety of chiral organic compounds. [3][4][5][6][7] The majority of literature-known methods for the preparation of a-hydroxysilanes are based on the asymmetric reduction of acylsilanes [8] or the hydrogenation of enolsilanes. [9] However, the synthesis of acylsilanes usually requires several steps. [10] An alternative, but less used, approach is the one previously described, which includes the addition of a silicon nucleophile to a carbonyl compound. [11][12][13][14] Hiyama et al. introduced a fluoride-catalyzed SiÀ Si bond cleavage followed by the addition of released silicon nucleophiles to aldehydes. [11] However, yields were partially diminished by [1,2]-Brook rearrangement. Barrett and Hill [13] elaborated a practical procedure based on the addition of easy-to-form Me 2 PhSiLi to aliphatic and aromatic aldehydes, but the use of such strongly basic nucleophiles is not without problems for functionalized aldehydes.Recently, Oestreich described the racemic 1,2-addition of a silicon nucleophile to imines and aldehydes, and proposed a mechanism involving a CuÀSi intermediate as the silyl transfer species. [2d, 15] The mild copper-mediated generation of nucleophilic silicon from Si À B compounds might therefore be useful for catalytic one-step access to enantiomerically pure a-hydroxysilanes from readily available aldehydes.Herein, we report the first enantiomeric version of the 1,2addition of a silicon nucleophile to aromatic and aliphatic aldehydes catalyzed by copper(I) complexes.Our investigation started with benzaldehyde, which was selected as a model substrate for initial screening. The reaction of 1 a with Me 2 PhSiBpin (2; = Si À B, pin = pinacolato) [16] in the presence of CuF(PPh 3 ) 3 ·2 MeOH (3) [17] as the copper catalyst was completed in 2 h at room temperature, and resulted in the isola...

In the typical procedure in the Experimental Section of this paper (see also the Supporting Information), the first sentence should read: "The aryl iodide (1.05 mmol) was dissolved in Et 2 O (0.5 mL) under an inert atmosphere and cooled to À55 8C before the addition of nBuLi (1.05 mmol, 656 mL, 1.6 m in hexanes)." The authors apologize for the oversight.

The transition metal-catalyzed transfer of silicon nucleophiles onto various electrophiles has recently gained considerable attention, due to the now readily available silicon pro-nucleophiles such as silylboronates. Our interest lies in the addition of such species to acid derivatives for the generation of acylsilanes. We report herein an efficient method to synthesize these compounds, starting from easyto-form anhydrides, with very good yields.

In der allgemeinen Vorschrift im experimentellen Teil dieser Zuschrift (vergleiche auch die Hintergrundinformationen) soll der erste Satz lauten: "Das Aryliodid (1.05 mmol) wurde in inerter Atmosphäre in Et 2 O (0.5 mL) gelçst und auf À55 8C gekühlt, bevor es mit nBuLi (1.05 mmol, 656 mL, 1.6 m in Hexan) umgesetzt wurde." Die Autoren bedauern das Übersehen.

Allylbenzene derivatives are ubiquitous frameworks in organic chemistry. Herein is described an efficient copper-catalyzed cross-coupling reaction using vinylsilanes and benzyl bromides, leading to the synthesis of allylbenzenes. This methodology allows the use of cis, trans and 1,1'-disubstituted vinylsilanes as well as a large number of sensitive moieties.