Development of Chiral, Bifunctional Thiosquaramides: Enantioselective Michael Additions of Barbituric Acids to Nitroalkenes
Development of Chiral, Bifunctional Thiosquaramides: Enantioselective Michael Additions of Barbituric Acids to Nitroalkenes
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DOI：
10.1021/jacs.7b01115
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发表时间：
2017-04-19
影响因子：
15
通讯作者：
Rawal, Viresh H.
中科院分区：
文献类型：
--
作者：
Rombola, Michael;Sumaria, Chintan S.;Rawal, Viresh H.
我们报告了一种合成手性硫代方酰胺的一般方法，这是一类以前文献中没有描述过的双功能催化剂。发现硫代方酰胺比它们的氧代方酰胺对应物更酸性并且显著更溶于非极性溶剂中，并且它们是用于巴比妥酸药效体与硝基烯烃的未报道的对映选择性共轭加成反应的优异催化剂，以高产率和高对映选择性提供手性巴比妥酸盐衍生物，即使催化剂负载低至0.05摩尔%。
We report a general method for the synthesis of chiral thiosquaramides, a class of bifunctional catalysts not previously described in the literature. Thiosquaramides are found to be more acidic and significantly more soluble in nonpolar solvents than their oxosquaramide counterparts, and they are excellent catalysts for the unreported, enantioselective conjugate addition reaction of the barbituric acid pharmacaphore to nitroalkenes, delivering the chiral barbiturate derivatives in high yields and high enantioselectivities, even with catalyst loadings as low as 0.05 mol%.