A New Type of Stereoselectivity in Baeyer-Villiger Reactions: Access to E- and Z-Olefins

作者：Zhang Zhi Gang; Roiban Gheorghe Doru; Pablo Acevedo Juan; Polyak Iakov; Reetz Manfred T^*

来源：Advanced Synthesis & Catalysis, 2013, 355(1): 99-106.

DOI：10.1002/adsc.201200759

• alkenes
• Baeyer-Villiger oxidation
• diastereoselectivity
• directed evolution
• palladium

A new concept for accessing configurationally defined trisubstituted olefins has been developed. Starting from a common ketone precursor of the type 4-ethylidenecyclohexanone, BaeyerVilliger monooxygenases are employed as catalysts in diastereoselective BaeyerVilliger reactions leading to the corresponding E- or Z-configurated lactones. Wild-type cyclohexanone monooxygenase (CHMO) as catalyst delivers the E-isomers and a directed evolution mutant the opposite Z-isomers. Subsequent transition metal-catalyzed chemical transformations of a key product containing a vinyl bromide moiety provide a variety of different trisubstituted E- or Z-olefins. A model based on QM/MM sheds light on the origin of this unusual type of diastereoselectivity. In contrast to this biocatalytic approach, traditional BaeyerVilliger reagents such as m-CPBA fail to show any selectivity, 1:1 mixtures of E- and Z-olefins being formed.

• 出版日期2013-1