- Hydrogen-Bonding-Promoted Cascade Rearrangement Involving the Enlargement of Two Rings: Efficient Access to Polycyclic Quinoline Derivatives
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An efficient cascade reaction of tryptamine-derived isocyanides with C,N-cyclic azomethine imines is described. The polycyclic pyrrolo[2,3-c]quinoline derivatives, which benefited from rearrangement process driven by hydrogen bonding, could be directly assembled in moderate to good yields (40–87 %) under metal-free and mild conditions. This transformation involved four new heterocyclic rings formations and uniquely, ring opening of indole as well as ring expansion of C,N-cyclic azomethine imine. Both experimental and DFT studies provided guidance on the in-depth insight into the reaction pathways and hydrogen bonding was identified to lower the free energy barrier in transition states. This work constitutes a rare example of tryptamine-derived isocyanide-based cascade reactions, and potentially could be a powerful synthetic strategy for accessing polycyclic analogues involved in natural products.
- Cao, Wen-Bin,Ji, Shun-Jun,Lan, Yu,Li, Haiyan,Li, Shijun,Xu, Meng-Meng,Xu, Xiao-Ping
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supporting information
p. 21425 - 21430
(2020/09/23)
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- CuBr2 catalyzed bromination/oxidation of isochromans to benzaldehyde derivatives
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A series of isochromans were oxidized and brominated by using 1.2 equiv of CuBr2 in CH3CN at reflux to give the corresponding bromo benzaldehydes in moderate yields. A plausible mechanism for this transformation has been suggested.
- Zhou, Mei-Yan,Kong, Shan-Shan,Zhang, Ling-Qiong,Zhao, Ming,Duan, Jin-Ao,Ou-Yang, Zhen,Wang, Min
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p. 3962 - 3964
(2013/07/25)
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- Comparative study of anionic and radical cyclization for the preparation of 1,3-dimethylindans: highly stereoselective preparation of cis-1,3-disubstituted indans via intramolecular carbolithiation.
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[reaction: see text] The preparation of 1,3-dimethylindans from 4-(2-bromophenyl)-1-pentene (1) and 2-(2-iodo-1-methylethyl)styrene (2) substrates via radical-mediated cyclization and intramolecular carbolithiation has been investigated. Although cyclization of the radical derived from either substrate proceeds with modest selectivity for the cis-isomer, as does cycloisomerization of the aryllithium derived from substrate 1 (cis/trans approximately 2), intramolecular cyclization of the alkyllithium derived from substrate 2 is a highly cis-selective process (cis/trans = 12).
- Bailey, William F,Mealy, Michael J,Wiberg, Kenneth B
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p. 791 - 794
(2007/10/03)
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