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[4 + 2] cycloadditions of N-alkenyl iminium ions: structurally complex heterocycles from a three-component Diels-Alder reaction sequence.

ABSTRACT: N-Alkenyl iminium ions serve as conduits to three-component [4 + 2] cycloaddition reactions accessing structurally and stereochemically diverse piperidine derivatives. These cationic 2-azadienes participate in endo- or exo-selective [4 + 2] cycloadditions with electron-rich and neutral alkene dienophiles to generate a tetrahydropyridinium ion as the initial cycloadduct. In situ nucleophilic addition to the cycloaddition-derived iminium ion completes the three-component coupling sequence and affords a versatile synthesis of structurally complex piperidines.

SUBMITTER: Sarkar N

PROVIDER: S-EPMC2762780 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature

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[4 + 2] cycloadditions of N-alkenyl iminium ions: structurally complex heterocycles from a three-component Diels-Alder reaction sequence.

Sarkar Nihar N Banerjee Abhisek A Nelson Scott G SG

Journal of the American Chemical Society 20080625 29

N-Alkenyl iminium ions serve as conduits to three-component [4 + 2] cycloaddition reactions accessing structurally and stereochemically diverse piperidine derivatives. These cationic 2-azadienes participate in endo- or exo-selective [4 + 2] cycloadditions with electron-rich and neutral alkene dienophiles to generate a tetrahydropyridinium ion as the initial cycloadduct. In situ nucleophilic addition to the cycloaddition-derived iminium ion completes the three-component coupling sequence and affo ...[more]

PMID: 18576626

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