Synthesis of Dihydropyridinone-Fused Indoles and α-Carbolines via N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of Indolin-2-imines and Bromoenals
作者:Liang Yi、Yuyang Zhang、Zhao-Fei Zhang、Dequn Sun、Song Ye
DOI:10.1021/acs.orglett.7b00820
日期:2017.5.5
The N-heterocyclic carbene catalyzed [3 + 3] annulation of indolin-2-imines and bromoenals was developed to give dihydropyridinone-fused indoles in good to high yields, which were transformed to α-carbolines with different 2-subsituents by a process of dehydrogenation, tosylation, and palladium catalyzed C–C or C–N coupling reaction.
N-Heterocyclic Carbene-Catalyzed Construction of 1,3,5-Trisubstituted Benzenes from Bromoenals and α-Cyano-β-methylenones
作者:Chun-Lin Zhang、Song Ye
DOI:10.1021/acs.orglett.6b03306
日期:2016.12.16
A direct and efficient approach to 1,3,5-trisubstituted benzenes has been developed via N-heterocycliccarbene-catalyzed [2 + 4] annulation of α-bromoenals and α-cyano-β-methylenones. The reaction worked well for both aryl- and alkylenones.
Formal [3 + 4] Annulation of α,β-Unsaturated Acyl Azoliums: Access to Enantioenriched N–<i>H</i>-Free 1,5-Benzothiazepines
作者:Chao Fang、Tao Lu、Jindong Zhu、Kewen Sun、Ding Du
DOI:10.1021/acs.orglett.7b01457
日期:2017.7.7
An unprecedented formal [3 + 4] annulation of α,β-unsaturatedacyl azoliums with 2-aminobenzenethiols has been utilized to synthesize enantioenriched N–H-free 1,5-benzothiazepines, which are recognized as privileged structures in numerous biologically active scaffolds. This protocol offers a rapid and direct pathway to access the target compounds with high enantioselectivities and has been applied
N‐Heterocycliccarbene‐catalyzed reactions of indolin‐3‐ones with 2‐bromoenals opened an asymmetric access to 3,4‐dihydropyrano[3,2‐b]indol‐2(5 H)‐ones in good yields and with good to excellent enantioselectivities. This protocol tolerates a broad substrate scope. In addition, a possible mechanism for the annulation reaction is presented.
A facile synthesis of tetrahydroimidazo[1,2-a]pyridines and tetrahydrobenzo[b]imidazo[1,2,3-ij][1,8]naphthyridines through NHC-catalyzed cascade annulations
A new efficient approach for the synthesis of tetrahydroimidazo[1,2-a]pyridines and tetrahydrobenzo[b]imidazo[1,2,3-ij][1,8]naphthyridines with biological significance was successfully developed through a NHC-catalyzed cascade C–C bond and C–N bond formation process. This new alternative approach for the assembly of these multi-functionalized nitrogen bridgehead-fused heterocycles features mild conditions
通过NHC催化的级联反应成功开发了一种新的高效合成四氢咪唑并[1,2- a ]吡啶和四氢苯并[ b ]咪唑并[1,2,3- ij ] [1,8]萘啶的新方法C–C键和C–N键的形成过程。组装这些多功能氮桥头稠合杂环的这种新的替代方法具有温和的条件,中等至高收率和操作简便性。