Copper-Catalyzed Cross-Coupling of Vinyliodonium Salts and Zinc-Based Silicon Nucleophiles
作者:Liangliang Zhang、Martin Oestreich
DOI:10.1021/acs.orglett.8b03714
日期:2018.12.21
A silylation of vinyliodonium salts using zinc-based silicon reagents as nucleophiles is reported. This cross-coupling is catalyzed by copper, and vinylsilanes are obtained in high yield likely following a Cu(I)/Cu(III) reaction mechanism. The procedure is operationally simple, neither air- nor moisture-sensitive, and tolerant of a range of functional groups. The new method is an addition to the still
Bench-Stable Stock Solutions of Silicon Grignard Reagents: Application to Iron- and Cobalt-Catalyzed Radical C(sp<sup>3</sup>
)-Si Cross-Coupling Reactions
作者:Weichao Xue、Ryosuke Shishido、Martin Oestreich
DOI:10.1002/anie.201807640
日期:2018.9.10
the preparation of silicon‐based magnesiumreagents is reported. The MgBr2 used in the lithium‐to‐magnesium transmetalation step is generated in situ from 1,2‐dibromoethane and elemental magnesium in hot THF. No precipitation of MgBr2 occurs in the heat, and transmetalation at elevated temperature leads to homogeneous stock solutions of the silicon Grignard reagents that are stable and storable in the
Copper‐Catalyzed Enantio‐ and Diastereoselective Addition of Silicon Nucleophiles to 3,3‐Disubstituted Cyclopropenes
作者:Liangliang Zhang、Martin Oestreich
DOI:10.1002/chem.201904272
日期:2019.11.13
A highly stereocontrolled syn-addition of silicon nucleophiles across cyclopropenes with two different geminal substituents at C3 is reported. Diastereomeric ratios are excellent throughout (d.r.≥98:2) and enantiomeric excesses usually higher than 90 %, even reaching 99 %. This copper-catalyzed C-Si bond formation closes the gap of the direct synthesis of α-chiral cyclopropylsilanes.
Preparation of optically active n-butyl(methyl)phenyl-, tert-butyl(methyl)phenyl- and isopropyl(methyl)phenylsilanes from the corresponding silyl chlorides using 2,2′-dihydroxy-1,1′-binaphthyls as resolving agents
Enantiomeric silanes 4a, 4b and 4c were obtained from the corresponding racemic silyl chlorides via diastereomeric derivatives with (R)-[1,1′]binaphthalenyl-2,2′-diol; the optical purity of silanes 4a and 4c was determined (>98% ee) by HPLC using a chiral cyclodextrin-based column.
Salt‐Stabilized Silylzinc Pivalates for Nickel‐Catalyzed Carbosilylation of Alkenes
作者:Jixin Wang、Zhili Duan、Xingchen Liu、Shoucheng Dong、Kaixin Chen、Jie Li
DOI:10.1002/anie.202202379
日期:2022.4.19
solid silylzincpivalate prepared from the silyllithium reagents via transmetalation with Zn(OPiv)2 is reported. These silylzincpivalates showed enhanced air and moisture stability and unique reactivity in the nickel-catalyzed regioselective alkyl and benzylsilylation of alkenes. Kinetic experiments highlighted the crucial involvement of OPiv-coordination in improving the reactivity of silylzinc pivalates