Cobalt-Catalyzed Selective Synthesis of Isoquinolines Using Picolinamide as a Traceless Directing Group
作者:Changsheng Kuai、Lianhui Wang、Bobin Li、Zhenhui Yang、Xiuling Cui
DOI:10.1021/acs.orglett.7b00702
日期:2017.4.21
first been employed as a traceless directing group for the cobalt-catalyzed oxidative annulation of benzylamides with alkynes to synthesize isoquinolines throughC–H/N–H bonds activation. Oxygen is used as a terminal oxidant. This protocol exhibits good functional group tolerance and excellent regioselectivity. Both terminal and internalalkynes can be efficiently applied to this catalytic system as substrates
The air‐stable and inexpensive Ni(dppe)Cl2 along with Et3N efficiently catalyzes the iminoannulation of alkynes at room temperature, allowing for the preparation of important 3,4‐disubstituted and 3‐substituted isoquinolines in high yields with complete regioselectivity. These annulation reactions feature a broad substrate scope, easy scalability, operational simplicity, and excellent practicality
Cobalt-Catalyzed<i>ortho</i>-C−H Functionalization/Alkyne Annulation of Benzylamine Derivatives: Access to Dihydroisoquinolines
作者:Ángel Manu Martínez、Nuria Rodríguez、Ramón Gómez-Arrayás、Juan C. Carretero
DOI:10.1002/chem.201702283
日期:2017.8.25
A practical picolinamide-directed C−H functionalization/alkyne annulation of benzylaminederivatives enabling access to the previously elusive 1,4-dihydroisoquinoline skeleton was developed using molecular O2 as the sole oxidant and Co(OAc)2 as precatalyst. The method is compatible with both internal and terminal alkynes and shows high versatility and functional-group tolerance. Furthermore, full preservation
Palladium-catalyzed enolate arylation as a key C–C bond-forming reaction for the synthesis of isoquinolines
作者:Ben S. Pilgrim、Alice E. Gatland、Carlos H. A. Esteves、Charlie T. McTernan、Geraint R. Jones、Matthew R. Tatton、Panayiotis A. Procopiou、Timothy J. Donohoe
DOI:10.1039/c5ob02320c
日期:——
those that give rise to the traditionally difficult to access electron-deficient isoquinoline skeletons. These two synthetic operations can be combined to give a three-component, one-pot isoquinoline synthesis. Alternatively, cyclization of the intermediates with hydroxylamine hydrochloride engenders direct access to isoquinoline N-oxides; and cyclization with methylamine, gives isoquinolinium salts. Significant
A Versatile Synthesis of Substituted Isoquinolines
作者:Chong Si、Andrew G. Myers
DOI:10.1002/anie.201104769
日期:2011.10.24
o‐tolualdehyde tert‐butylimines were shown to condense with nitriles to form eneamido anion intermediates that were trapped in situ with various electrophiles, thus affording a diverse array of highly substitutedisoquinolines, many of which are difficult to access by known methods. Further substitutional diversification was achieved by modification of the work‐up conditions and by subsequent transformations.