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Enantioselective Michael addition to vinyl phosphonates via hydrogen bond-enhanced halogen bond catalysis.

ABSTRACT: An asymmetric Michael addition of malononitrile to vinyl phosphonates was accomplished by hydrogen bond-enhanced bifunctional halogen bond (XB) catalysis. NMR titration experiments were used to demonstrate that halogen bonding, with the support of hydrogen-bonding, played a key role in the activation of the Michael acceptors through the phosphonate group. This is the first example of the use of XBs for the activation of organophosphorus compounds in synthesis. In addition, the iodo-perfluorophenyl group proved to be a better directing unit than different iodo- and nitro-substituted phenyl groups. The developed approach afforded products with up to excellent yields and diastereoselectivities and up to good enantioselectivities.

SUBMITTER: Kaasik M

PROVIDER: S-EPMC8171314 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature

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Enantioselective Michael addition to vinyl phosphonates <i>via</i> hydrogen bond-enhanced halogen bond catalysis.

Kaasik Mikk M Martõnova Jevgenija J Erkman Kristin K Metsala Andrus A Järving Ivar I Kanger Tõnis T

Chemical science 20210426 21

An asymmetric Michael addition of malononitrile to vinyl phosphonates was accomplished by hydrogen bond-enhanced bifunctional halogen bond (XB) catalysis. NMR titration experiments were used to demonstrate that halogen bonding, with the support of hydrogen-bonding, played a key role in the activation of the Michael acceptors through the phosphonate group. This is the first example of the use of XBs for the activation of organophosphorus compounds in synthesis. In addition, the iodo-perfluorophen ...[more]

PMID: 34163847

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