72657-23-9Relevant articles and documents
A robust and stereocomplementary panel of ene-reductase variants for gram-scale asymmetric hydrogenation
Nett, Nathalie,Duewel, Sabine,Schmermund, Luca,Benary, Gerrit E.,Ranaghan, Kara,Mulholland, Adrian,Opperman, Diederik J.,Hoebenreich, Sabrina
, (2021/01/25)
We report an engineered panel of ene-reductases (ERs) from Thermus scotoductus SA-01 (TsER) that combines control over facial selectivity in the reduction of electron deficient C[dbnd]C double bonds with thermostability (up to 70 °C), organic solvent tolerance (up to 40 % v/v) and a broad substrate scope (23 compounds, three new to literature). Substrate acceptance and facial selectivity of 3-methylcyclohexenone was rationalized by crystallisation of TsER C25D/I67T and in silico docking. The TsER variant panel shows excellent enantiomeric excess (ee) and yields during bi-phasic preparative scale synthesis, with isolated yield of up to 93 % for 2R,5S-dihydrocarvone (3.6 g). Turnover frequencies (TOF) of approximately 40 000 h?1 were achieved, which are comparable to rates in hetero- and homogeneous metal catalysed hydrogenations. Preliminary batch reactions also demonstrated the reusability of the reaction system by consecutively removing the organic phase (n-pentane) for product removal and replacing with fresh substrate. Four consecutive batches yielded ca. 27 g L?1 R-levodione from a 45 mL aqueous reaction, containing less than 17 mg (10 μM) enzyme and the reaction only stopping because of acidification. The TsER variant panel provides a robust, highly active and stereocomplementary base for further exploitation as a tool in preparative organic synthesis.
Catalytic Asymmetric Construction of Halogenated Stereogenic Carbon Centers by Direct Vinylogous Mannich-Type Reaction
Zhong, Feng,Yue, Wen-Jun,Zhang, Hai-Jun,Zhang, Cheng-Yuan,Yin, Liang
supporting information, p. 15170 - 15175 (2018/11/30)
A catalytic asymmetric vinylogous Mannich-type reaction of γ-halo-α,β-unsaturated N-acylpyrazoles and N-Boc-aldimines was disclosed, which afforded an array of halogenated (F-, Cl-, and Br-) allylic stereogenic carbon centers in high yields with good to high regio-, diastereo-, and enantioselectivities. The brominated product served as a suitable electrophile for common SN2 nucleophilic substitution and copper-mediated SN2′ allylic alkylation with metal reagents. The utility of present methodology was demonstrated by the asymmetric synthesis of a common intermediate toward the synthesis of two chiral 2,3-disubstituted piperidine pharmaceuticals.
Cell-free protein engineering of Old Yellow Enzyme 1 from Saccharomyces pastorianus
Quertinmont, Leann T.,Lutz, Stefan
, p. 7282 - 7287 (2016/10/29)
In protein engineering, cell-free transcription/translation of linear mutagenic DNA templates can tremendously accelerate and simplify the screening of enzyme variants. Using the RApid Parallel Protein EvaluatoR (RAPPER) protocol, we have evaluated the impact of amino acid substitutions and loop truncations on substrate specificity and stereoselectivity of Old Yellow Enzyme 1 from Saccharomyces pastorianus. Our study demonstrates the benefit of systematically assessing amino acid variations including substrate profiling to explore sequence-function space.
