Bentler P, Bergander K, Daniliuc CG, Mück‐Lichtenfeld C, Jumde RP, Hirsch AKH, Gilmour R. Inverting Small Molecule-Protein Recognition by the Fluorine Gauche Effect: Selectivity Regulated by Multiple H→F Bioisosterism.
Angew Chem Int Ed Engl 2019;
58:10990-10994. [PMID:
31157945 PMCID:
PMC6771710 DOI:
10.1002/anie.201905452]
[Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/31/2019] [Indexed: 12/31/2022]
Abstract
Fluorinated motifs have a venerable history in drug discovery, but as C(sp3 )-F-rich 3D scaffolds appear with increasing frequency, the effect of multiple bioisosteric changes on molecular recognition requires elucidation. Herein we demonstrate that installation of a 1,3,5-stereotriad, in the substrate for a commonly used lipase from Pseudomonas fluorescens does not inhibit recognition, but inverts stereoselectivity. This provides facile access to optically active, stereochemically well-defined organofluorine compounds (up to 98 % ee). Whilst orthogonal recognition is observed with fluorine, the trend does not hold for the corresponding chlorinated substrates or mixed halogens. This phenomenon can be placed on a structural basis by considering the stereoelectronic gauche effect inherent to F-C-C-X systems (σ→σ*). Docking reveals that this change in selectivity (H versus F) with a common lipase results from inversion in the orientation of the bound substrate being processed as a consequence of conformation. This contrasts with the stereochemical interpretation of the biogenetic isoprene rule, whereby product divergence from a common starting material is also a consequence of conformation, albeit enforced by two discrete enzymes.
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