Selective Synthesis of Diverse Spiro-oxindole-fluorene Derivatives via a DABCO-Promoted Annulation Reaction of Bindone and 3-Methyleneoxindoles
作者:Dan Liu、Xueyan Liu、Jing Sun、Chao-Guo Yan
DOI:10.1021/acs.joc.1c01513
日期:2021.11.5
base-promoted annulation reaction of bindone and 3-phenacylideneoxindoles in DCM at room temperature afforded spiro[indeno[1,2-a]fluorene-5,3′-indoline] derivatives in good yields and with high diastereoselectivity. However, the similar reaction of 2-(2-oxoindolin-3-ylidene) acetates resulted in Z/E-isomeric spiro[indeno[1,2-a]fluorene-5,3′-indolines] with diastereomeric ratios of 2:1 to 10:1. On the other hand
DABCO 促进的 bindone ([1,2'-biindenylidene]-1',3,3'-trione) 和 3-methyleneoxindoles 的环化反应在不同的反应条件下表现出非常有趣的分子多样性。在室温下,bindone 和 3-phenacylideneoxindoles 在 DCM 中碱促进的环化反应以良好的收率和高非对映选择性提供螺[茚并[1,2- a ]芴-5,3'-二氢吲哚] 衍生物。然而,2-(2-oxoindolin-3-ylidene) 醋酸酯的类似反应导致Z / E-异构螺[茚并[1,2- a]fluorene-5,3'-indolines],非对映体比例为 2:1 至 10:1。另一方面,DABCO促进的bindone和3-亚甲氧基吲哚在不同温度下在乙腈中的环化反应选择性地得到螺[苯并[5,6]pentaleno[1,6 a - b ]naphthalene-7