Site-specific role of bifunctional graphitic carbon nitride catalyst for the sustainable synthesis of 3,3-spirocyclic oxindoles in aqueous media
作者:Anshu Dandia、Dinesh Kumar Mahawar、Pratibha Saini、Surendra Saini、Shyam L. Gupta、Kuldeep S. Rathore、Vijay Parewa
DOI:10.1039/d1ra03881h
日期:——
Functionalized graphitic carbon nitride (Sg-C3N4) has been manufactured and used as a reusable catalyst for the one-pot production of various spiro-pyrano chromenes and spiro indole-3,1′-naphthalene tetracyclic systems in aqueous media. An ultrasound-assisted method has been used for the functionalization of g-C3N4. The catalytic functionalities and the structural integrity of the catalyst were characterized
功能化石墨氮化碳 (Sg-C 3 N 4 ) 已被制造并用作可重复使用的催化剂,用于在水介质中一锅法生产各种螺吡喃色烯和螺吲哚-3,1'-萘四环体系。超声辅助方法已用于 gC 3 N 4的功能化。通过不同的分析工具表征催化剂的催化功能和结构完整性。Sg-C 3 N 4的催化位点特异性作用通过一锅反应序列中的各种对照实验得到证实。我们认识到 Sg-C 3 N 4作为第一个反应序列的双功能酸碱催化剂,而在各种螺吡喃色烯的单锅生产过程中,它是第二个反应序列的酸性催化剂。此外,Sg-C 3 N 4的双功能酸碱催化作用对于第一个反应序列已被证实,而在螺吲哚-3,1'-萘四环体系的一锅法生产过程中,它对第二个反应序列具有基本催化作用。多种 C-C、C-O 和 C-N 键、六元环、立体中心和螺骨架在单一反应中形成,增强了杀菌性能,并可能导致发现新的药用特性。Sg-C 3 N 4的温和反应环境、简单的后处
Organocatalytic enantioselective construction of multi-functionalized spiro oxindole dienes
作者:Xiao-Fei Huang、Ya-Fei Zhang、Zheng-Hang Qi、Nai-Kai Li、Zhi-Cong Geng、Kun Li、Xing-Wang Wang
DOI:10.1039/c4ob00545g
日期:——
A diastereo- and enantio-selective domino Michael-cyclization–tautomerization reaction of isatylidene malononitriles with α,α-dicyanoalkenes catalyzed by a cinchona alkaloid-derived bifunctional thiourea catalyst has been developed. A series of multi-functionalized spiro oxindole diene derivatives have been obtained in good to excellent yields (up to 97%) with good to excellent enantioselectivities (up to 96%) as well as good diastereoselectivities (up to 7.9 : 1). In addition, an anomalous temperature effect on the enantioselectivity has also been studied for this transformation.
A novel method for the synthesis of functionalized spirocyclic oxindoles by one-pot tandem reaction of vinyl malononitriles with isatylidene malononitriles
作者:Thelagathoti Hari Babu、A. Abragam Joseph、D. Muralidharan、Paramasivan T. Perumal
DOI:10.1016/j.tetlet.2009.12.082
日期:2010.2
One-pot synthesis of novel spirocyclicoxindoles was achieved via vinylogous Michael addition of vinyl malononitriles on isatin–malononitrile adducts as the keystep followed by a sequential tandem reaction.
Enantioselective sequential vinylogous Michael addition–cyclization reactions of vinyl malononitriles with isatylidene malononitrile were accomplished usingl-proline derived bifunctional thiourea.