Lipase Catalyzed Enantioselective Hydrolysis of (±)-2-Acetoxy-1-chloro-3-phthalimidopropane

2-Methyltetrahydrofuran as a suitable green solvent for phthalimide functionalization promoted by supported KF

“…As can be seen from Table 3 temperature is really influential, using the same conditions it is possible to minimize the formation of product 5, corresponding to chlorine substitution, simply by increasing temperature from 60 • C to reflux (entries 1-2). It is worth highlighting that when both enantiopure forms of epichlorohydrin (entries 3-4) were used, the regioselective ringopening occurred in parallel with a very good stereospecificity, thus improving previous procedures described 25 for the synthesis of optically active 4b and 4c, which are crucial building blocks in the synthesis of b-adrenergic blocking agents. 26 The efficiency of the proposed N-functionalization protocol was afterwards confirmed also in the case of substituted phthalimides (Table 4).…”

Development of a novel chemoenzymatic route to enantiomerically enriched β-adrenolytic agents. A case study toward propranolol, alprenolol, pindolol, carazolol, moprolol, and metoprolol

“…Initially, we performed lipase-catalyzed hydrolytic resolution of the corresponding acetate rac - 5 under kinetically-controlled conditions following the procedure reported by Gelo and Šunjić. 25 Disappointingly, in our hands, hydrolytic KR of rac - 5 using native lipase from Pseudomonas ( Burkholderia ) cepacia (Amano PS) suspended in a homogenous mixture of 0.1 M aqueous K 2 HPO 4 buffer (pH 7.5) and EtOH (90 : 10 v/v) failed as this protocol allowed to obtain faster-reacting enantiomer ( S )-(−)- 4 with a moderate enantiomeric excess (80% ee), and the remaining acetate ( R )-(−)- 5a with only 21% ee. In addition, this reaction proceeded with unsatisfactory enantioselectivity ( E = 11) and low rate (21% conv.…”