Efficient Synthesis of Isoquinoline Derivatives via AgOTf/Cu(OTf)2-Cocatalyzed Cyclization of 2-Alkynyl Benzaldoxime
摘要:
An efficient, AgOTf and Cu(OTf)(2) multicatalytic intramolecular cycloisomerization of 2-alkynylbenzaldoxime is reported. Isoquinoline N-oxides have been found to be deoxygenated to the corresponding quinolines in good yields in dimethylformamide/dichloroethane (v/v 5:1) as solvent at 120 degrees C.
a selective phosphoranation of alkynes with phosphoniumcation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols
Palladium-Catalyzed CH Oxidation of Isoquinoline N-Oxides: Selective Alkylation with Dialkyl Sulfoxides and Halogenation with Dihalo sulfoxides
作者:Bo Yao、Ren-Jie Song、Yan Liu、Ye-Xiang Xie、Jin-Heng Li、Meng-Ke Wang、Ri-Yuan Tang、Xing-Guo Zhang、Chen-Liang Deng
DOI:10.1002/adsc.201101009
日期:2012.7.9
palladium‐catalyzed CHoxidation of isoquinoline N‐oxides has been developed for regioselectively synthesizing substituted isoquinolines. The method represents the first example of using dialkylsulfoxides as the alkyl sources for the construction of 1‐alkylated isoquinolines. Moreover, the regioselective halogenation of isoquinoline N‐oxides is also successful using dihalosulfoxides as the halide sources
We report geometry-dependent cyclizations of o-alkynylaryl ketoximes and nitrones catalyzed by goldcomplexes. (E)-Ketoximes undergo N-attack to give isoquinoline-N-oxides. In sharp contrast, (Z)-ketoximes undergo unprecedented O-nucleophilic attack, followed by a redoxcascade leading to a novel catalytic entry to isoindoles of diverse scope. The structure of an isoindole was unambiguously supported
A highly efficient method for the facile access of isoquinolines and isoquinoline N-oxides via a Cu(i)-catalyzed intramolecular cyclization of (E)-2-alkynylaryl oxime derivatives in water has been developed. This protocol was performed under simple and mild conditions without organic solvent, additives or ligands. By switching on/off a hydroxyl protecting group of oximes, the selective N-O/O-H cleavage
Activating Group Recycling in Action: A Rhodium-Catalyzed Carbothiolation Route to Substituted Isoquinolines
作者:Milan Arambasic、Joel F. Hooper、Michael C. Willis
DOI:10.1021/ol402650q
日期:2013.10.18
A new rhodium(l) catalyst allows practical and efficient alkyne carbothiolation reactions to be achieved on synthetically useful ketone-bearing aryl methyl sulfides. The carbothiolation adducts, featuring a 'recycled methyl sulfide' activating group, are convenient precursors to highly substituted isoquinolines.