A Short Asymmetric Synthesis of the Benzopyrano[3,4-<i>c</i>]pyrrolidine Core<i>via</i>an Organocatalytic Domino Oxa-Michael/Michael Reaction
作者:Chuan Wang、Xuena Yang、Gerhard Raabe、Dieter Enders
DOI:10.1002/adsc.201200472
日期:2012.10.8
A short and highly stereoselective asymmetric synthesis of 3,4-trans-disubstituted chromans employing nitrovinylphenols and acrolein as precursors via a domino oxa-Michael/Michael reaction is described. This cascade was efficiently catalyzed by diphenylprolinol TMS ether furnishing the products in good to excellent yields (62–91%) and excellent stereoselectivities (dr: 94:6–97:3, 93–98% ee). The domino
描述了一种短的且高度立体选择性的不对称合成3,4-反式-二取代的苯并二氢吡喃,其利用硝基乙烯基苯酚和丙烯醛作为前体经由多米诺基-氧杂-迈克尔/迈克尔反应来合成。该联苯被二苯基脯氨醇TMS醚有效地催化,提供的产品具有良好至优异的收率(62–91%)和出色的立体选择性(dr:94:6-97:3,93-98%ee)。可以通过还原性胺化/ N-烷基化序列将多米诺产物转化为相应的N-烷基化的反-苯并吡喃并[3,4- c ]吡咯烷。对于S33138的去氰基衍生物的情况证明了这一点。