EtOH-mediated cascade C(sp3)–H alkylation via aromatization-driven [1,6]-hydride transfer: green and divergent synthesis of spirocyclic azepino[4,3,2-cd]indoles†
Yao-Bin Shen, Qian-Hao Zhuang, Xiao-Lin Wang, Xiao-De An, Bin Qiu, Tiesheng Shi and Jian Xiao
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引用次数: 0
Abstract
The development of green and efficient methods for the construction of azepinoindole skeletons remains highly desirable yet challenging. Described herein are the EtOH-mediated cascade C(sp3)–H alkylation reactions of 4-dialkylamino-indole-3-carbaldehydes for green and divergent synthesis of spirocyclic azepino[4,3,2-cd]indole derivatives. This protocol proceeded through a cascade in situ assembly of pre-aromatics/aromatization-driven [1,6]-hydride transfer/cyclization sequence, which exhibited many advantages such as green bio-sourced EtOH as the reaction medium, metal-free and redox-neutral conditions, high step-/atom-economy, water as waste, high yields, excellent diastereoselectivities (up to >20 : 1 dr), a wide substrate scope, and diverse transformations.
期刊介绍:
Green Chemistry is a journal that provides a unique forum for the publication of innovative research on the development of alternative green and sustainable technologies. The scope of Green Chemistry is based on the definition proposed by Anastas and Warner (Green Chemistry: Theory and Practice, P T Anastas and J C Warner, Oxford University Press, Oxford, 1998), which defines green chemistry as the utilisation of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Green Chemistry aims to reduce the environmental impact of the chemical enterprise by developing a technology base that is inherently non-toxic to living things and the environment. The journal welcomes submissions on all aspects of research relating to this endeavor and publishes original and significant cutting-edge research that is likely to be of wide general appeal. For a work to be published, it must present a significant advance in green chemistry, including a comparison with existing methods and a demonstration of advantages over those methods.