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Diastereo- and enantioselective hydrogenative aldol coupling of vinyl ketones: design of effective monodentate TADDOL-like phosphonite ligands.

ABSTRACT: We report the first enantioselective reductive aldol couplings of vinyl ketones, which were achieved through the design of a novel monodentate TADDOL-like phosphonite ligand. Specifically, hydrogenation of commercially available methyl vinyl ketone (MVK) or ethyl vinyl ketone (EVK) in the presence of aldehydes 1a-7a using cationic rhodium catalysts modified by chiral TADDOL-like phosphonite ligands AP-I and AP-IV produces aldol adducts 1b-7b and 1c-7c with excellent control of relative and absolute stereochemistry. The absolute stereochemical assignments of the aldol adducts are made in analogy to that determined for the 5-bromophthalimido derivative of aldol adduct 1b and the 2-bromo-5-nitrobenzoate of 3b, which were established by single-crystal X-ray diffraction analysis using the anomalous dispersion method.

SUBMITTER: Bee C

PROVIDER: S-EPMC2860773 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature

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Diastereo- and enantioselective hydrogenative aldol coupling of vinyl ketones: design of effective monodentate TADDOL-like phosphonite ligands.

Bee Cisco C Han Soo Bong SB Hassan Abbas A Iida Hiroki H Krische Michael J MJ

Journal of the American Chemical Society 20080212 9

We report the first enantioselective reductive aldol couplings of vinyl ketones, which were achieved through the design of a novel monodentate TADDOL-like phosphonite ligand. Specifically, hydrogenation of commercially available methyl vinyl ketone (MVK) or ethyl vinyl ketone (EVK) in the presence of aldehydes 1a-7a using cationic rhodium catalysts modified by chiral TADDOL-like phosphonite ligands AP-I and AP-IV produces aldol adducts 1b-7b and 1c-7c with excellent control of relative and absol ...[more]

PMID: 18266373

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