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
Diastereoselective aldol reactions of β-silylenolates: a new regiocontrolled synthesis of allylsilanes
作者:Lan Fleming、Achintya K. Sarkar
DOI:10.1039/c39860001199
日期:——
Allylsilanes are prepared stereospecifically trans(10) or cis(12) and with complete regiocontrol by decarboxylative elimination of the β-hydroxy acids (9).
Regiochemistry in the hydroboration of allylsilanes
作者:Ian Fleming、Nicholas J. Lawrence
DOI:10.1016/s0040-4039(00)87838-7
日期:——
The hydroboration of most types of allylsilane is highly selective for the formation of the product having the silicon and boron in a 1,3 relationship when the hydroboratingagent is 9-BBN. There is only a low degree of correlation between the difference in the chemical shifts of the trigonal carbon atoms on an alkene and the regioselectivity in hydroboration with either borane:THF or 9-BBN.
Regiocontrolled allylsilane synthesis from secondary allylic alcohol derivatives
作者:Ian Fleming、Andrew P. Thomas
DOI:10.1039/c39850000411
日期:——
Unsymmetrical secondaryallylic acetates and urethanes react with the dimethyl(phenyl)silylcuprate reagent to give allylsilanes with fair to good regioselectivity.
The stereochemistry of osmylation, epoxidation, and methylenation of allylsilanes
作者:Ian Fleming、Achintya K. Sarkar、Andrew P. Thomas
DOI:10.1039/c39870000157
日期:——
The stereochemistry of attack on an allylsilane is more selective when the substituent on the chiral centre carrying the silyl group is larger than a methyl group, as shown by the reactions of the allylsilanes (5) and (12) with osmium tetroxide, m-chloroperbenzoic acid, and Yamamoto's methylenation reagent.