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
Reactions of Silylmethyl Allylic Silanes: Synthesis of Tetrahydrofurans
作者:K. A. Woerpel、Jacqueline H. Smitrovich
DOI:10.1055/s-2002-35988
日期:——
to provide tetrahydrofurans, bearing up to five stereogenic centers, as single diastereomers. These annulation processes are likely facilitated because the reactions proceed via carbocations that are stabilized by two β-silyl substituents.