Enantio- and diastereoselective Michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea.
Enantio- and diastereoselective Michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea.
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DOI：
10.1002/chin.200521033
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发表时间：
2005-01
影响因子：
15
通讯作者：
Tomotaka Okino;Yasutaka Hoashi;T. Furukawa;Xuenong Xu;Y. Takemoto
中科院分区：
文献类型：
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作者：
Tomotaka Okino;Yasutaka Hoashi;T. Furukawa;Xuenong Xu;Y. Takemoto
我们合成了一类新的双功能催化剂，在手性支架上带有一个硫脲基团和一个氨基。其中含3,5-二（三氟甲基）苯和二甲胺基的硫脲1e在1,3-二羰基化合物与硝基烯烃的不对称Michael反应中效率较高。此外，我们还通过Michael反应开发了一种新的(R)-(-)-巴氯芬和具有高对映选择性的手性季碳中心的合成路线。在这些反应中，我们假设催化剂的硫脲部分和氨基分别激活了硝基烯烃和1,3-二羰基化合物，以提供具有高对映选择性和非对映选择性的Michael加合物。
We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins. Furthermore, we have developed a new synthetic route for (R)-(-)-baclofen and a chiral quaternary carbon center with high enantioselectivity by Michael reaction. In these reactions, we assumed that a thiourea moiety and an amino group of the catalyst activates a nitroolefin and a 1,3-dicarbonyl compound, respectively, to afford the Michael adduct with high enantio- and diastereoselectivity.