Rh2(II)-Catalyzed Nitro-Group Migration Reactions: Selective Synthesis of 3-Nitroindoles from β-Nitro Styryl Azides
摘要:
Rhodium carboxylate complexes (1 mol %) catalyze the migration of electron-withdrawing groups to selectively produce 3-substituted indoles from beta-substituted styryl azides. The relative order of migratorial aptitude for this transformation is ester << amide < H < sulfonyl < benzoyl << nitro.
Merging Gold Catalysis and Brønsted Acid Catalysis for the Synthesis of Tetrahydrobenzo[<i>b</i>][1,8]naphthyridines
作者:Ruxia Yi、Xincheng Li、Boshun Wan
DOI:10.1002/adsc.201701323
日期:2018.3.1
A gold(I)/Brønsted acid‐catalyzed cyclization of 2‐azidobenzaldehydes with 3‐aza‐1,6‐enynes has been developed for the synthesis of tetrahydrobenzo[b][1,8]naphthyridine derivatives. This protocol enabled the modular synthesis of tetracyclic heterocycles in one operation with water and nitrogen gas as the byproducts.
已经开发了金(I)/布朗斯台德酸催化的3-叠氮基-1,6-炔烃对2-叠氮基苯甲醛的环化反应,以合成四氢苯并[ b ] [1,8]萘啶衍生物。该方案能够在一次操作中以水和氮气为副产物,以模块化方式合成四环杂环。
Cu-Catalyzed Cascade Annulation of Alkynols with 2-Azidobenzaldehydes: Access to 6<i>H</i>-Isochromeno[4,3-<i>c</i>]quinoline
作者:Xiao-Feng Mao、Xiao-Ping Zhu、Deng-Yuan Li、Pei-Nian Liu
DOI:10.1021/acs.joc.7b00937
日期:2017.7.7
A copper-catalyzedcascade reaction of alkynols and 2-azidobenzaldehydes has been achieved, giving 6H-isochromeno[4,3-c]quinoline in yields of 40–81%. This reaction provides a novel, concise strategy for rapidly constructing compounds with fused N- and O-containing heterocycles. In contrast to previously reported reactions of alkynols in which the first step is intramolecular cycloisomerization, the
铜催化的炔醇和2-叠氮基苯甲醛的级联反应已经实现,得到6 H-异色酚[4,3- c ]喹啉,产率为40-81%。该反应提供了一种用于快速构建化合物与稠合的N A新颖,简洁策略-和O -含有杂环。与先前报道的炔醇的反应第一步是分子内环异构化相反,炔醇的这种新反应的第一步是熵不利的分子间加成。然后将所得的半缩醛中间体进行分子内环化和芳构化以提供产物。
De novo Synthesis of Chiral 3,4‐DihydroquinazolinesviaOne‐Pot Enantioselective Ugi‐Azide/Cyclization Sequences†
Herein, we reported a precise de novo synthesis of chiral 3,4-dihydroquinazoline frameworks via a one-pot anionic stereogenic-at-cobalt(III) complex-catalyzed enantioselective Ugi-azide/Pd-catalyzed cyclization sequence. This powerful protocol involves 5 components and 2 catalytic systems, delivering chiral 3,4-dihydroquinazolines with excellent enantioselectivities (up to 94% ee). The preliminary