4-Dimethylamino Pyridine-Promoted One-Pot Three-Component Regioselective Synthesis of Highly Functionalized 4<i>H</i>-Thiopyrans via Heteroannulation of β-Oxodithioesters
作者:Rajiv Kumar Verma、Girijesh Kumar Verma、Gaurav Shukla、Anugula Nagaraju、Maya Shankar Singh
DOI:10.1021/co200203e
日期:2012.3.12
A highly convergent and regioselective heteroannulation protocol for the synthesis of hitherto unreported highly substituted 2-amino-4-(aryl/alkyl)-5-(aroyl/heteroaroyl)-3-(cyano/carboalkoxy)-6-methylthio-4H-thiopyran derivatives has been developed. This one-pot three-component domino coupling of β-oxodithioesters, aldehydes, and malononitrile/ethyl or methyl cyanoacetate is promoted by 4-dimethylamino
对于迄今未报告高度取代的2-氨基-4-(芳基/烷基)-5-(芳酰基/杂芳基)-3-(氰基/烷氧羰基)-6-甲硫基-4-合成的高度会聚和区域选择性杂环化协议ħ -已经开发了硫吡喃衍生物。β-氧代二硫代酸酯,醛和丙二腈/氰基乙酸乙酯或氰基乙酸甲酯的这种一锅式三组分多米诺偶联在溶剂(二氯甲烷(DCM))中以及在无溶剂条件下由4-二甲基氨基吡啶(DMAP)促进。反应参数的系统优化确定了三组分偶联(3CC)方案可耐受多种功能,可提供密集功能化的4 H-thiopyrans具有出色的产量。这种级联的Knoevenagel缩合/ Michael加成/环化序列的优点在于其高原子经济性,出色的产率以及在一次操作中产生三个新键(两个CC和一个CS)和一个立体中心的效率。