Abstract In contrast to many chemical dihydroxylation methods, enzymatic epoxide hydrolysis provides an environmentally benign route to vicinal diols, which are important intermediates in the synthesis of fine chemicals and pharmaceuticals. Using epoxide hydrolases, enantiopure diols are accessible under mild conditions. In order to assess the selectivity of epoxide hydrolases on geraniol‐derived oxiranes, a range of derivatives were screened against a large variety of enzyme preparations. For nearly all substrates, a matching hydrolase with excellent enantioselectivity (≥95% ee ) could be found. In addition, a chemoenzymatic approach for the stereoselective synthesis of furanoid linalool oxide was developed. Combination of enzymatic enantioselective hydrolysis with stereoselective Tsuji‐Trost reaction granted diastereoselective access to trans ‐(2 R ,5 R )‐configured linalool oxide with high diastereomeric and enantiomeric excess (97% de and 97% ee ). magnified image
We report the intramolecular Tsuji–Trost reaction of Ugi adducts to give spiro-diketopiperazines in high yield and with high enantioselectivity. This approach allows the catalytic asymmetric construction of a broad range of these medicinally important heterocycles under mild conditions, in two steps from cheap, commercially available starting materials.
Complex polycyclic molecular scaffolds containing multiple stereocenters, as found in many natural products, present particularly appealing targets for synthetic chemists. In addition to the academic challenge of selectively constructing these intricate frameworks, many such compounds display valuable bioactivities, making them important starting points for drug discovery. As in many aspects of contemporary organic synthesis, catalysis plays a key role in many MBFTs toward biologically relevant molecules (BRMs). Recently developed catalytic methodologies allow novel types of C–C bond formations and/or unprecedented control over the stereochemical outcome of the reaction. This chapter focuses on MBFTs based on recent developments in organocatalysis and transition metal catalysis, as well as multicomponent chemistry. It also aims to demonstrate the scope and synthetic potential of the above-mentioned classes of MBFTs in the synthesis of BRMs, with illustrative examples ranging from natural products to complex pharmaceuticals.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
A palladium-catalyzed intermolecular cascade (4+3) cyclocondensation of salicylaldehydes and vinylcyclopropanes is reported. A key feature of the reaction is the use of a phosphonate group as an acceptor moiety on the cyclopropane, exploiting its propensity to undergo olefination with aldehydes. Subsequent O-allylation enabled the formation of a range of substituted benzoxepinsWith a novel chiral ligand, the products were obtained in generally good yield and with reasonable enantioselectivity.
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