Metal-free and regiospecific synthesis of 3-arylindoles
作者:Chuangchuang Xu、Wenlai Xie、Jiaxi Xu
DOI:10.1039/d0ob00317d
日期:——
arylhydrazine hydrochlorides and Fischer indolization. The organic base triethylamine plays a crucial role in the final elimination step in the Fischer indole synthesis, affording 3-arylindoles regiospecifically. The reaction features advantages of microwave acceleration, non-metal participation, short reaction time, organic acid-base co-catalysis, and broad substrate scope.
A practical protocol to synthesize 3-substituent-2-(azol-1-yl)indolederivatives has been developed via an electrochemical oxidative cross coupling process under mild conditions. This electro-oxidative C–N bond formation strategy tolerates a range of functional groups and is amenable to gram scale synthesis. Moreover, this method was applied to the late-stage functionalization of bioactive molecules
A palladium‐catalyzed intermolecular dynamic kinetic asymmetric dearomatization of 3‐arylindoles with internal alkynes was developed with the use of achiral Xantphos and chiral sulfinamide phosphine ligand (PC‐Phos) as the co‐ligands. This method could deliver various spiro[indene‐1,3′‐indole] compounds in good yields (up to 95 % yield) with up to 98 % ee. The salient features of the transformation
Concise Assembly of the Polycyclic Frameworks Associated with the Hapalindole and Fischerindole Alkaloids
作者:Martin G. Banwell、Xinghua Ma、Rebecca M. Taylor、Anthony C. Willis
DOI:10.1021/ol062020x
日期:2006.10.1
N-methylindole (4) with 6,6-dibromobicyclo[3.1.0]hexane (5) in the presence of silver tetrafluoroborate affords conjugate 7 in 67% yield. This product can be readily elaborated to compounds 12b and 13b which embody the polycyclic frameworks associated with members of the hapalindole and fischerindole classes of alkaloids. The chiral-auxiliary-substituted 6,6-dibromobicyclo[3.1.0]hexanes 21 and 22 react
metal-catalyzed C–Hborylation has been one of the most notable advances in synthetic chemistry and has been widely employed in the preparation of organoboron reagents. Due to economic and heavy-metal-residue concerns, there is significant interest in the development of metal-free processes to mimic metallic systems. Here, we disclose a highly efficient metal-free approach for the directedC–Hborylation of C3-substituted