Stereoselective Michael Additions of Phosphorylated Allyl Carbanions − Synthesis of Functionalized Cyclopentylphosphonates and Phosphane Oxides
作者:Wen Juan Ruan、Alfred Hassner
DOI:10.1002/1099-0690(200104)2001:7<1259::aid-ejoc1259>3.0.co;2-d
日期:2001.4
Dimethyl (2-chloromethyl-2-propenyl)phosphonate (3b) and (tert-butyl)[2-(chloromethyl)-2-propenyl](phenyl)phosphane oxide (3d) were prepared and their reactions with α,β-unsaturated esters 5a−c and ketone 5d, acting as phosphorylated trimethylenemethane equivalents by a [3+2] strategy, were investigated. With the use of LDA in the presence of DMPU, the Michael addition proceeded with high stereoselectivity
制备了(2-氯甲基-2-丙烯基)膦酸二甲酯(3b)和(叔丁基)[2-(氯甲基)-2-丙烯基](苯基)膦氧化物(3d),并使其与α,β-不饱和反应研究了通过[3 + 2]策略充当磷酸三亚甲基甲烷当量的酯5a - c和酮5d的情况。在DMPU存在下使用LDA,迈克尔加成反应以高的立体选择性和区域选择性进行,得到亚甲基环戊基取代的二甲基膦酸酯或(叔丁基)(苯基)膦氧化物衍生物6a - d和14(S P)。化合物3d与5a - b和5d反应生成磷非对映异构体10(R P)和11(S P),12(R P)和13(S P)以及16(R P)和17(S P),在5-亚甲基环戊烷的三个立体异构中心具有完全的立体选择性,均具有1,2-反式和2,3-反式立体化学。开链的形成顺式加成物15 2,3-和顺式二取代的环戊烷化合物18(小号P)也可以实现。通过1D和2D NMR光谱确定所有产物的立体化学特征。