|
Organostannane addition reactions comprise the nucleophilic addition of an allyl-, allenyl-, or propargylstannane to an aldehyde, imine, or, in rare cases, a ketone.〔Gung, B.W. ''Org. React.'' 2004, ''64'', 1-112.〕 Organostannane addition to carbonyl groups constitutes one of the most common and efficient methods for the construction of contiguous, oxygen-containing stereocenters in organic molecules. As many molecules containing this motif—polypropionates and polyacetates, for instance—are desired by natural products chemists, the title reaction has become important synthetically and has been heavily studied over the years.〔Denmark, S. E.; Weber, E. J. ''J. Am. Chem. Soc.'' 1984, ''106'', 7970.〕〔Keck, G. E.; Dougherty, S. M.; Savin, K. A. ''J. Am. Chem. Soc.'' 1995, ''117'', 6210.〕 Substituted allylstannanes may create one or two new stereocenters, often with a very high degree of stereocontrol. Advantages: Organostannanes are known for their stability, ease of handling, and selective reactivity. Chiral allylstannanes often react with great stereoselectivity to give single diastereomers, and models explaining the sense of selectivity are reliable. Disadvantages: Stoichiometric amounts of metal-containing byproducts are generated during the reaction. Additions to sterically encumbered pi bonds, such as those of ketones, are uncommon. :File:Alstan.png ==Mechanism and Stereochemistry== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Organostannane addition」の詳細全文を読む スポンサード リンク
|
