Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021, India.
J Org Chem. 2010 Jan 15;75(2):472-5. doi: 10.1021/jo9021327.
L-proline-catalyzed three-component reactions of ethyl 2-[(2-oxo-2-arylethyl)sulfonyl]acetate or ethyl 2-[(2-ethoxy-2-oxoethyl)sulfonyl]acetate, aromatic aldehydes, and 5-aryltetrahydro-3-thiophenone furnished a variety of highly substituted thieno[3,2-c]thiopyran derivatives. This facile transformation presumably occurs via a one-pot domino sequence of enamine formation/aldol condensation/Michael addition/6-exo-trig cyclization/elimination and involves the creation in a single operation of three C-C bonds and the generation of three new stereocenters with complete diastereoselectivity in all cases and a fourth one in ca. 7:3 diastereomeric ratio when starting from a 5-substituted tetrahydro-3-thiophenone derivative.
L-脯氨酸催化的乙基 2-[(2-氧代-2-芳基乙基)磺酰基]乙酸酯或乙基 2-[(2-乙氧基-2-氧代乙基)磺酰基]乙酸酯、芳香醛和 5-芳基四氢-3-噻吩酮的三组分反应，提供了各种高度取代的噻吩并[3,2-c]噻喃衍生物。这种简便的转化可能通过烯胺形成/醛缩合/Michael 加成/6-endo-trig 环化/消除的一锅法多米诺序列发生，并且在所有情况下都涉及单个操作中三个 C-C 键的形成以及三个新的立体中心的生成，并且在从 5-取代的四氢-3-噻吩酮衍生物开始时，在约 7:3 的非对映选择性比下生成第四个立体中心。
