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Catalytic Asymmetric [4 + 2] Additions with Aliphatic Nitroalkenes.

ABSTRACT: We describe an unprecedented cycloaddition reaction of 2-pyrones with aliphatic nitroalkenes catalyzed by a new bifunctional cinchona alkaloid-derived catalyst bearing a bulky TIPS-ether at the 9-position. The [2.2.2] bicyclic adducts were obtained in good yield with excellent diastereo- and enantioselectivity. Carbon isotope effects were measured by (13)C NMR and are indicative of a stepwise mechanism. Finally, a synthetic application is demonstrated, highlighting the utility of the cycloadducts.

SUBMITTER: Bartelson KJ

PROVIDER: S-EPMC3235653 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature

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Catalytic Asymmetric [4 + 2] Additions with Aliphatic Nitroalkenes.

Bartelson Keith J KJ Singh Ravi P RP Foxman Bruce M BM Deng Li L

Chemical science 20111001 10

We describe an unprecedented cycloaddition reaction of 2-pyrones with aliphatic nitroalkenes catalyzed by a new bifunctional cinchona alkaloid-derived catalyst bearing a bulky TIPS-ether at the 9-position. The [2.2.2] bicyclic adducts were obtained in good yield with excellent diastereo- and enantioselectivity. Carbon isotope effects were measured by (13)C NMR and are indicative of a stepwise mechanism. Finally, a synthetic application is demonstrated, highlighting the utility of the cycloadduct ...[more]

PMID: 22174973

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