Xiong Q, Dong S, Chen Y, Liu X, Feng X. Asymmetric synthesis of tetrazole and dihydroisoquinoline derivatives by isocyanide-based multicomponent reactions.
Nat Commun 2019;
10:2116. [PMID:
31073191 PMCID:
PMC6509109 DOI:
10.1038/s41467-019-09904-5]
[Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/03/2019] [Indexed: 11/24/2022] Open
Abstract
Although isocyanide-based multicomponent reactions were proven to be simple, elegant and facile strategies for the synthesis of highly valuable nitrogen-containing heterocycles, their asymmetric versions accessing to optically active nitrogen heterocyclic compounds are rather limited. Here, we illustrate that, relying on the enantioselective addition of simple isocyanides to C=C bonds, several isocyanide-based multicomponent reactions are realized in the presence of a chiral MgII-N,Nʹ-dioxide catalyst. In the reaction among isocyanide, TMSN3, and alkylidene malonate, three- or four-component reactions could be precisely controlled by modulating reaction conditions, supplying two types of enantioenriched tetrazole-derivatives in moderate to high yields. Possible catalytic cycles via a key zwitterionic intermediate, and the vital roles of H2O or excess ligand are provided based on control experiments. Moreover, taking advantage of this zwitterionic intermediate as a 1,3-dipole, an enantioselective dearomative [3+2] annulation reaction of nonactivated isoquinolines is achieved, furnishing chiral 1,2-dihydroisoquinolines in good to excellent results.
Asymmetric isocyanide-based multicomponent reactions are elegant, yet challenging, strategies to access valuable N-heterocycles. Here, the authors employ a chiral Mg(II) -N,N′-dioxide catalyst in three- or four-component reactions to obtain chiral tetrazoles and devise a dearomative [3+2] annulation reaction of isoquinolines.
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