Stereoselective Synthesis of (<i>Z</i>)- and (<i>E</i>)-Allylic Silanes by Copper-Mediated Substitution Reactions of Allylic Carbamates with Grignard Reagents
作者:Jacqueline H. Smitrovich、K. A. Woerpel
DOI:10.1021/jo991312r
日期:2000.3.1
Both (Z)- and (E)-allylic silanes were prepared with high stereoselectivity by the copper-mediated substitution of allylic carbamates by organometallic reagents. The reaction of alkylmagnesium reagents with (E)-allylic carbamates provides (Z)-allylic silanes, whereas both alkylmagnesium and alkyllithium reagents react with (Z)-allylic carbamates to afford (E)-allylic silanes. Because Grignard reagents
R3SiMgMe and MnCl2 are disclosed. (1) The manganese species reacted with terminal acetylenes to give 1,2-disilylated 1-alkenes. Mono- and bis(trimethylsilyl) acetylenes gave tri- and tetrasilylated ethenes, respectively, in good yields. Highly strained tetrakis(trimethylsilyl) ethene has now become easily accessible by this technique. (2) The reaction of alkenyl halides, alkenyl sulfides, and enol phosphates
Enantioselective Synthesis of α-Aminosilanes by Copper-Catalyzed Hydroamination of Vinylsilanes
作者:Nootaree Niljianskul、Shaolin Zhu、Stephen L. Buchwald
DOI:10.1002/anie.201410326
日期:2015.1.26
The synthesis of α‐aminosilanes by a highly enantio‐ and regioselective copper‐catalyzed hydroamination of vinylsilanes is reported. The system employs Cu‐DTBM‐SEGPHOS as the catalyst, diethoxymethylsilane as the stoichiometric reductant, and O‐benzoylhydroxylamines as the electrophilic nitrogen source. This hydroamination reaction is compatible with differentially substituted vinylsilanes, thus providing