Synlett 2007(13): 2106-2110  
DOI: 10.1055/s-2007-984882
LETTER
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Morita-Baylis-Hillman Reaction Catalyzed by Simple Amino Alcohol Derived Thioureas

Alessandra Lattanzi*
Dipartimento di Chimica, Università di Salerno, Via Ponte don Melillo, 84084, Fisciano, Italy
Fax: +39(089)969603; e-Mail: lattanzi@unisa.it;
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Publikationsverlauf

Received 19 May 2007
Publikationsdatum:
12. Juli 2007 (online)

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Abstract

Thioureas straightforwardly derived from commercially available enantiopure amino alcohols have been found to promote the asymmetric Morita-Baylis-Hillman reaction of 2-cyclohexen-1-one and different aldehydes in the presence of triethylamine under solvent-free conditions. The corresponding allylic alcohols were obtained in good to high yields and up to 88% ee.

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The following solvents were employed at a concentration of 2 M with respect to the aldehyde: toluene, MeOH, MeCN, THF, CH2Cl2.

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Typical Procedure for the MBH Reaction To a capped vial containing catalyst 1f (22.4 mg, 0.04 mmol) was added 2-cyclohexen-1-one (78 mL, 0.8 mmol) and Et3N (4.4 mL, 0.04 mmol). The mixture was stirred for 5 min and then the aldehyde was added (0.2 mmol). After 100-147 h, the reaction was directly purified by flash silica gel chromatography eluting with PE-Et2O mixtures (98:2 to 80:20) to give a clear oil. Spectral data of allylic alcohols matched those reported in the literature.2,3,5