Identification of an Esterase Isolated Using Metagenomic Technology which Displays an Unusual Substrate Scope and its Characterisation as an Enantioselective Biocatalyst
作者:Declan P. Gavin、Edel J. Murphy、Aoife M. Foley、Ignacio Abreu Castilla、F. Jerry Reen、David F. Woods、Stuart G. Collins、Fergal O'Gara、Anita R. Maguire
DOI:10.1002/adsc.201801691
日期:2019.6.6
Evaluation of an esterase annotated as 26D isolated from a marine metagenomic library is described. Esterase 26D was found to have a unique substratescope, including synthetic transformations which could not be readily effected in a synthetically useful manner using commercially available enzymes. Esterase 26D was more selective towards substrateswhich had larger, more sterically demanding substituents
New asymmetricconjugatereduction of beta,beta-disubstituted alpha,beta-unsaturated ketones and esters was accomplished with alkoxylhydrosilanes in the presence of chiral rhodium(2,6-bisoxazolinylphenyl) complexes in high yields and high enantioselectivity. (E)-4-Phenyl-3-penten-2-one and (E)-4-phenyl-4-isopropyl-3-penten-2-one were readily reduced at 60 degrees C in 95 % ee and 98 % ee, respectively
Pyrrolidine‐Based P,O Ligands from Carbohydrates: Easily Accessible and Modular Ligands for the Ir‐Catalyzed Asymmetric Hydrogenation of Minimally Functionalized Olefins
作者:Pilar Elías‐Rodríguez、Carlota Borràs、Ana T. Carmona、Jorge Faiges、Inmaculada Robina、Oscar Pàmies、Montserrat Diéguez
DOI:10.1002/cctc.201801485
日期:2018.12.7
The potential of P,O‐iminosugar based ligands in the Ir‐catalyzed asymmetric hydrogenation of minimallyfunctionalizedolefins is presented. These new ligands were prepared from easily available carbohydrates (D‐mannose, D‐ribose and D‐arabinose). The stereochemical and polyfunctional diversity of carbohydrates allowed the modulation of the ligands, both from their electronic properties and the rigidity
Giving a Second Chance to Ir/Sulfoximine-Based Catalysts for the Asymmetric Hydrogenation of Olefins Containing Poorly Coordinative Groups
作者:Maria Biosca、Oscar Pàmies、Montserrat Diéguez
DOI:10.1021/acs.joc.9b00829
日期:2019.6.21
This work identifies a family of Ir/phosphite-sulfoximine catalysts that has been successfully used in the asymmetrichydrogenation of olefins with poorly coordinative or noncoordinative groups. In comparison with analogue Ir/phosphine-sulfoximine catalysts previously reported, the presence of a phosphite group extended the range of olefins than can be efficiently hydrogenated. High enantioselectivities
Chiral rhodium(bisoxazolinylphenyl) complexes reduced α,β-unsaturatedesters in high enantioselectivity up to 97-98% ee in the combination of alkoxyhydrosilanes.