The cyclization reactions of methylthioacetanilides mediated by manganese(HI) acetate and/or copper(111) acetate are described. Indolinones and indolinediones can be produced effectively via a 5-membered ring cyclization of methylthioacetanilides. The product distributions are highly dependent on the reaction conditions. In most cases, the electronic effect of the substituents on the aryl ring was found to significantly affect the yields of cyclization products. This cyclization reaction proceeded faster with manganese(HI) acetate/copper(II) acetate. (C) 2003 Elsevier Science Ltd. All rights reserved.
Lanthanide Silylamide-Catalyzed Synthesis of Pyrano[2,3-<i>b</i>]indol-2-ones
作者:Qifa Chen、Yue Teng、Fan Xu
DOI:10.1021/acs.orglett.1c01506
日期:2021.6.18
A lanthanide silylamide-catalyzed tandem reaction of isatins, diethyl phosphite, and 2,3-diarylcyclopropenones has been developed. A series of pyrano[2,3-b]indol-2-ones were synthesized in high yields. The cooperation of the Lewis acidity of the lanthanide center and the Bronsted basicity of the N(SiMe3)2 anion may be the key factor affecting the catalytic activity of lanthanide amides.
已经开发了镧系元素甲硅烷基酰胺催化的靛红、亚磷酸二乙酯和 2,3-二芳基环丙烯酮的串联反应。以高产率合成了一系列吡喃并[2,3 - b ]indol-2-ones。镧系元素中心的路易斯酸度和N(SiMe 3 ) 2阴离子的布朗斯台德碱度的协同作用可能是影响镧系酰胺催化活性的关键因素。
N-Heterocyclic carbene-catalyzed [4 + 2] cyclization of α,β-unsaturated carboxylic acids bearing γ-H with isatins: an enantioselective synthesis of spirocyclic oxindole–dihydropyranones
作者:Ling Zhu、Chenxia Yu、Tuanjie Li、Yuhong Wang、Yinan Lu、Wenjing Wang、Changsheng Yao
DOI:10.1039/c5ob02160j
日期:——
An NHC-catalyzed asymmetric [4 + 2] annulation of isatins and α,β-unsaturated carboxylicacids bearing γ-H gave spirocyclic oxindole–dihydropyranones successfully via an in situactivationstrategy. This protocol featured easy availability of raw materials, good yields and excellent enantioselectivities (up to 99% ee).
NHC-catalyzed oxidative γ-addition of α,β-unsaturated aldehydes to isatins: a high-efficiency synthesis of spirocyclic oxindole-dihydropyranones
作者:Rui Liu、Chenxia Yu、Zhaoxin Xiao、Tuanjie Li、Xiangshan Wang、Yuanwei Xie、Changsheng Yao
DOI:10.1039/c3ob42008f
日期:——
This manuscript discloses an efficient construction of the spirocyclic oxindole-dihydropyranone scaffold via the N-heterocyclic carbene (NHC)-catalyzed oxidative γ-functionalization of α,β-unsaturated aldehydes bearing γ-H with isatin derivatives. The ready availability of the starting materials, easy work-up, mild reaction conditions and the potential utilization value of the products make this strategy attractive.
<i>N</i>-Heterocyclic-Carbene-Catalyzed Reaction of α-Bromo-α,β-Unsaturated Aldehyde or α,β-Dibromoaldehyde with Isatins: An Efficient Synthesis of Spirocyclic Oxindole-Dihydropyranones
Smooth as isatin! A straightforward synthesis of spirocyclic oxindole–dihydropyranones through an N‐heterocyclic‐carbene‐catalyzed [4+2] annulation of α‐bromo‐α,β‐unsaturated aldehydes or α,β‐dibromoaldehyde bearing γ‐H with isatin derivatives under mild reaction conditions is disclosed (see scheme). The concise construction, ready availability of the starting materials, avoidance of external oxidants