Enantioselective monoreduction of different 1,2-diaryl-1,2-diketones catalysed by lyophilised whole cells from Pichia glucozyma

Base‐Free Asymmetric Transfer Hydrogenation of 1,2‐Di‐ and Monoketones Catalyzed by a (NH)2P2‐Macrocyclic Iron(II) Hydride

“…[2] However,t he base additives that are required to activate the precatalyst [3] tend to limit the reaction scope.A ne minent example are ahydroxy ketones,f or example,b enzoin (A)o r, more generically,a cyloins (Figure 1), whose base-labile stereocenter easily racemizes upon heating or in basic media, [4] making the asymmetric hemihydrogenation of 1,2-diketones aformidable challenge. [9] Their synthesis has been accomplished by an umber of chemical and biocatalytic [7] methods such as the stoichiometric [10] and catalytic [11] oxidation of enolates or enol ethers,a lkene ketohydroxylation, [9] oxidative kinetic resolution, [12] dynamic kinetic resolution, [13] monooxidation of 1,2-diols, [14] benzoin condensation, [15] Friedel-Crafts reactions, [16] enzymatic reductions, [17] and asymmetric hydrosilylation with chiral frustrated [9] Their synthesis has been accomplished by an umber of chemical and biocatalytic [7] methods such as the stoichiometric [10] and catalytic [11] oxidation of enolates or enol ethers,a lkene ketohydroxylation, [9] oxidative kinetic resolution, [12] dynamic kinetic resolution, [13] monooxidation of 1,2-diols, [14] benzoin condensation, [15] Friedel-Crafts reactions, [16] enzymatic reductions, [17] and asymmetric hydrosilylation with chiral frustrated…”

Enzymatic reduction of acetophenone derivatives with a benzil reductase from Pichia glucozyma (KRED1-Pglu): electronic and steric effects on activity and enantioselectivity

“…The recombinant benzil ketoreductase KRED1-Pglu was isolated from the non-conventional yeast Pichia glucozyma; 16 whole cells of P. glucozyma enantioselectively reduced different aromatic ketones, [18][19][20] including acetophenone, with a marked preference for the formation of (S)-1-phenylethanol; 21,22 interestingly, KRED1-Pglu was isolated from the same yeast reduced acetophenone as a recombinant protein with opposite enantioselectivity. KRED1-Pglu was initially investigated using different para-substituted acetophenone derivatives (1a-1c and 1e-1h); acetophenone (1d) was considered as a reference ( Table 1).…”

Palladium‐Catalyzed Enantioselective Decarboxylative Allylic Alkylation of Protected Benzoin‐Derived Enol Carbonates

“…In a nitrogen-filled glovebox, a solution of Pd 2 (dba) 3 (1.8 mg) and L4 (3.9 mg) in MeCy (4 mL) was stirred for 30 minutes at 25°C, then the resulting solution was added to a vial containing allyl enol carbonate substrate (0.2 mmol) in MeCy (4 mL). The vial was sealed with a Teflon-lined cap, removed from the glovebox, and stirred at 25°C for 12 h. The crude reaction mixture was concentrated then purified by silica gel flash chromatography to provide the desired alkylation product.…”

“…[1] As a result, extensive efforts toward the asymmetric synthesis of benzoin derivatives have been reported, including enantioselective benzoin condensations, [2] reductions of αdiketones, [3] and enzyme-catalyzed kinetic resolutions. [1] As a result, extensive efforts toward the asymmetric synthesis of benzoin derivatives have been reported, including enantioselective benzoin condensations, [2] reductions of αdiketones, [3] and enzyme-catalyzed kinetic resolutions.…”