Synthesis of Enantioenriched Homopropargylic Sulfonamides by a Three Component Reaction of Aldehydes, Sulfonamides, and Chiral Allenylsilanes
作者:Ryan A. Brawn、James S. Panek
DOI:10.1021/ol901692n
日期:2009.10.1
Enantioenriched allenylsilanes are used as carbon nucleophiles in three-component reactions with in situgenerated N-sulfonylimines to selectively form syn-homopropargylic sulfonamides. The reactions proceed with a variety of aldehyde and sulfonamide reaction partners. These novel reaction products are obtained with useful levels of diastereoselectivity, and the axial chirality of the allenylsilane
对映体富集的丙二烯基硅烷在三组分反应中用作碳亲核试剂,与原位生成的N-磺酰亚胺选择性地形成顺-高炔丙基磺酰胺。反应在各种醛和磺酰胺反应伙伴下进行。这些新的反应产物具有有用的非对映选择性水平,并且丙二烯基硅烷的轴向手性完全转移到点手性,形成具有 >97% ee 的产物。
Annulations of Enantioenriched Allenylsilanes with in Situ Generated Iminium Ions: Stereoselective Synthesis of Diverse Heterocycles
作者:Ryan A. Brawn、James S. Panek
DOI:10.1021/ol802618p
日期:2009.1.15
mediated annulations with in situ generated iminium ions derived from tert-butyl carbamate and methyl carbamate to selectively form functionalized 4,5-dihydropyrroles and 4,5-dihyrooxazines, respectively. The dihydropyrrole products were further elaborated in a stereocontrolled vinylsilane terminated cyclization with in situ generated oxoniumions, resulting in pyranopyrroles.