Photoredox/Enzymatic Catalysis Enabling Redox-Neutral Decarboxylative Asymmetric C-C Coupling for Asymmetric Synthesis of Chiral 1,2-Amino Alcohols.

Photocatalysis offers tremendous opportunities for enzymes to access new functions. Herein, we described a redox-neutral photocatalysis/enzymatic catalysis system for the asymmetric synthesis of chiral 1,2-amino alcohols via decarboxylative radical C-C coupling of -arylglycines and aldehydes by combining an organic photocatalyst, eosin Y, and carbonyl reductase RasADH. Notably, this protocol avoids using any sacrificial reductants.

Semirational Engineering of a Thermostable Carbonyl Reductase for the Precision Synthesis of (2,3)-2-Methyl-2-benzyl-3-hydroxycyclopentanone and Its Analogues.

2,2-Disubstituted-3-hydroxycyclopentanones are important chiral intermediates for natural products and pharmaceuticals. Through semirational engineering of a thermostable carbonyl reductase CBCR from sp. BIS7, a mutant L91C/F93I was obtained.

Engineering a Carbonyl Reductase for Scalable Preparation of (S)-3-Cyclopentyl-3-hydroxypropanenitrile, the Key Building Block of Ruxolitinib.

(S)-3-Cyclopentyl-3-hydroxypropanenitrile is the key precursor for the synthesis of ruxolitinib. The bioreduction of 3-cyclopentyl-3-ketopropanenitrile (1 a) offers an attractive method to access this important compound. A carbonyl reductase (PhADH) from Paraburkholderia hospita catalyzed the reduction of 1 a giving the (S)-alcohol (1 b) with 85 % ee.

Highly Diastereoselective Synthesis of 2,2-Disubstituted Cyclopentane-1,3-diols via Stepwise Ketone Reduction Enabling Concise Chirality Construction.

A series of 2,2-disubstituted ,s-cyclopentane-1,3-diols were synthesized in >99% dr through enzymatic reduction of enantiopure 2,2-disubstituted 3-hydroxycyclopentane-1-ones, which were prepared by highly stereoselective enzymatic reduction of the corresponding cyclodiketones. For 2-benzyl-2-methyl-3-oxocyclopentyl acetate, acetylation of the hydroxyl group significantly affected the reduction stereoselectivity, giving ,s-, ,-, and ,-2-benzyl-2-methyl-cyclopentane-1,3-diols in stereomerically pure form. This efficient and environmentally friendly method provides a practical approach to the synthesis of these chiral building blocks in single stereoisomeric form, demonstrating the power of biocatalysis in the concise chirality construction of complex chiral molecules.

[A study on the stability of miniscrew on different loading time as orthodontic anchorage].

Purpose: To evaluate the stability of the miniscrew on different loading time as orthodontic anchorage.

Methods: 2 healthy adult male Beagle dogs were used in this study. 48 mini-implants were implanted into the maxilla and mandible of the dogs.