33442-47-6Relevant articles and documents
Auxiliary-Directed Diastereoselectivity in the Claisen Rearrangement of Glycolate Esters
Kallmerten, James,Gould, Thomas J.
, p. 1152 - 1155 (1986)
Examples are presented in which the stereochemical course of the Claisen rearrangement of allylic glycolates is controlled by a chiral substituent appended to the glycolate hydroxyl.
Identification of an Esterase Isolated Using Metagenomic Technology which Displays an Unusual Substrate Scope and its Characterisation as an Enantioselective Biocatalyst
Gavin, Declan P.,Murphy, Edel J.,Foley, Aoife M.,Castilla, Ignacio Abreu,Reen, F. Jerry,Woods, David F.,Collins, Stuart G.,O'Gara, Fergal,Maguire, Anita R.
, p. 2466 - 2474 (2019/03/11)
Evaluation of an esterase annotated as 26D isolated from a marine metagenomic library is described. Esterase 26D was found to have a unique substrate scope, including synthetic transformations which could not be readily effected in a synthetically useful manner using commercially available enzymes. Esterase 26D was more selective towards substrates which had larger, more sterically demanding substituents (i. e. iso-propyl or tert-butyl groups) on the β-carbon, which is in contrast to previously tested commercially available enzymes which displayed a preference for substrates with sterically less demanding substituents (e.g. methyl group) at the β-carbon. (Figure presented.).
Impact of variation of the acyl group on the efficiency and selectivity of the lipase-mediated resolution of 2-phenylalkanols
Foley, Aoife M.,Gavin, Declan P.,Joniec, Ilona,Maguire, Anita R.
, p. 1144 - 1153 (2017/09/15)
By tuning the steric properties of the acyl group to control the efficiency and selectivity of the resolution, 2-phenyl-1-propanol 1a was prepared by lipase-catalysed hydrolysis using a short-chain acyl group, with E-values of up to 66 (ee up to 95%). 2-Phenylbutan-1-ol 1b was similarly resolved (up to 86% ee) using the optimised conditions, while the ester of the more sterically demanding 3-methyl-2-phenylbutan-1-ol 1c proved resistant to enzymatic hydrolysis under these conditions.
Filling the gaps in the challenging asymmetric hydroboration of 1,1-disubstituted alkenes with simple phosphite-based phosphinooxazoline iridium catalysts
Magre, Marc,Biosca, Maria,Pmies, Oscar,Diguez, Montserrat
, p. 114 - 120 (2015/01/30)
We have identified a readily accessible phosphinooxazoline-based phosphite-oxazoline catalytic system, (S)-4-isopropyl-2-{2-[(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite]-phenyl}-2-oxazoline (L1a), that can hydroborate a range of 1,1-disubstituted aryl olefins with high enantioselectivity (up to 94%), excellent yields and perfect regioselectivity. The new phosphite-oxazoline ligands efficiently hydroborate a broader range of olefins than previous phosphinooxazoline ligands. In particular, a wide range of α-tert-butylstyrenes can be hydroborated that bear aryl substituents with different electronic and steric properties, which complements previous results with N-heterocyclic copper catalysts, the only other system reported to date that has achieved these reactions.