An efficient and expedient approach for the synthesis of unsymmetrical 3,3′-Bis-indolylmethanes via silica gel-mediated Friedel-Craftsalkylation of 3-indolylmethanols with diverse indoles is described. The synthetic utility of this transformation was demonstrated by reusing silica gel up to 10 times without apparent loss of reactivity .
This work describes an efficient α-alkylation reaction of α-amino aldehydes with 3-indolylmethanols. In the promotion of catalyst 3f, the target products were obtained in high yields (up to 99%), good diastereoselectivities (up to 88:12), and excellent enantioselectivities (up to 96% ee). The direct alkylation products can be readily converted into other tryptophan derivatives without the loss of stereoselectivities
Construction of Novel Tetrahydro-<i>β</i>-carboline-1-thione Spirooxindoles by Brønsted Acid Mediated Formal [3+3] Cyclization of 3-Indolylmethanols with 3-Isothiocyanato Oxindoles
p‐Toluenesulfonic acid mediated formal [3+3] cyclization of 3‐indolylmethanols with 3‐isothiocyanato oxindoles was realized. This transformation allowed for the synthesis of a series of novel tetrahydro‐β‐carboline‐1‐thione spirooxindoles in moderate to excellent yields (up to 99%) with generally good diastereoselectivities (up to >20:1). The structure of one product was determined by an X‐ray crystal
The catalytic direct dehydrative coupling of an alkene with an alcohol is one of the most straightforward and green strategies for the formation of Csp2−Csp2 bonds. However, previously reported studies have only dealt with achiral reactions. Here, we describe chiral Brønsted acid‐catalyzed direct catalyticasymmetric dehydrative coupling reactions of 3‐vinylindoles and 3‐indolylmethanols. Various structurally
Brønsted acid promoted C–C bond formation between indolylmethyl electrophiles and ketene dithioacetals: Diastereoselective synthesis of highly functionalized cyclopenta[b]indoles
作者:Santosh D. Jadhav、Tavinder Singh、Anand Singh
DOI:10.1016/j.tetlet.2020.152349
日期:2020.9
method for the construction of carbon–carbon bonds between α-substituted indolylmethyl electrophiles and ketene dithioacetals is described. This strategy was utilized to access 2,3-disubstituted cyclopenta[b]indoles via formal [3+2] cycloadditions. Readily available indolyl methanols and α-indolyl-α-amino carbonyl compounds serve as electrophiles upon activation by p-toluenesulfonic acid (PTSA) and react
描述了一种布朗斯台德酸促进的方法,用于在α取代的吲哚基甲基亲电子试剂和乙烯酮二硫缩醛之间建立碳-碳键。利用该策略通过正式的[3 + 2]环加成反应获得2,3-二取代的环戊[ b ]吲哚。现成的吲哚基甲醇和α-吲哚基-α-氨基羰基化合物经p活化后可作为亲电子试剂-甲苯磺酸(PTSA)与乙烯酮二硫缩醛反应,形成两个碳-碳键和一个具有出色的非对映选择性的五元环。采用结构相关的吲哚基前体以实现分子多样性的优势被关键的替代作用所突显,这些作用突出了机理上的差异并指导了反应的发展。