Intramolecular carbenoid insertions into thiophene: Reactions of 1-diazo-3-(2-thienyl)-2-propanone and 1-diazo-3-(3-thienyl)-2-propanone
作者:Christopher S. Frampton、David L. Pole、Kelvin Yong、Alfredo Capretta
DOI:10.1016/s0040-4039(97)01131-3
日期:1997.7
cyclopropanation followed by acid-catalyzed ring opening and tautomerization to yield 5,6-dihydro-4H-cyclopenta[b]thiopen-5-one. Under the same conditions, however, the isomeric 1-diazo-3-(3-thienyl)-2-propanone generates a cyclopropane intermediate which undergoes [4+2] cycloreversion, isomerization and Diels-Alder dimerization to give a complex spiro-disulphide. While the 2-substituted thiophene behaves like
用催化乙酸铑(II)处理1-重氮-3-(2-噻吩基)-2-丙酮可导致环丙烷化,然后进行酸催化的开环和互变异构反应,得到5,6-二氢-4 H-环戊基[ b ] thiopen-5-one。然而,在相同条件下,异构体1-重氮-3-(3-噻吩基)-2-丙酮生成环丙烷中间体,该中间体经历[4 + 2]环还原,异构化和Diels-Alder二聚化,生成复杂的螺二硫键。虽然2-取代的噻吩的行为类似于噻吩基系列的其他同源成员,但异构的3-取代的噻吩经历了以前类似呋喃基化合物所见的化学反应。讨论了对由PM3级别的初步分子建模提供的机制基础的见解。