Lipase-catalyzed kinetic resolution of racemic 1-(10-alkyl-10H-phenothiazin-3-yl)ethanols and their butanoates

Efficient and Stable Magnetic Chitosan-Lipase B from Candida Antarctica Bioconjugates in the Enzymatic Kinetic Resolution of Racemic Heteroarylethanols

“…The racemic substrates rac-2a-d,g,i,j were obtained through chemical reduction with sodium borohydride of the corresponding prochiral heretoarylmethylketones 1a-d,g,i,j, while the heretoarylethanols rac-2e,f,h were obtained by Grignard reaction from the corresponding aldehydes 1e,f,h. Further, the racemic ethanols were used as substrates in the enzymatic transesterification reactions and also as starting materials for the synthesis of the corresponding racemic acetates rac-3a-j, used to set-up the chromatographic separation methods (Scheme 1) [16][17][18]54].…”

“…The synthesis of the investigated racemic substrates rac-2a-j and products rac-3a-j was performed using known methods [16][17][18]54]. The racemic heteroarylethanols were obtained from the corresponding heteroarylmethylketones (compounds 1a-d,g,i,j) by chemical reduction with sodium borohydride or from the corresponding aldehydes (compounds 1e,f,h) by Grignard reaction.…”

“…While enzymatic kinetic resolutions of racemic 1-heteroarylethanols mediated by lipases have been already reported [12][13][14][15][16][17][18][19], herein in our aim to develop robust biocatalysts for process scale-up, immobilization of CaL-B through covalent binding is approached, to obtain stable, storable, easy to handle and as consequence recyclable immobilized lipase preparations, required for preparative scale processes [20,21]. Among the available support materials, nanosupports present several advantages, the immobilized enzymes are available on a large surface diffusion barrier-free, the suspension is free from sedimentation and approximates the behavior of a homogeneous liquid, but their separation is not simple.…”

A robust and efficient lipase based nanobiocatalyst for phenothiazinyl-ethanol resolution

“…[37][38][39][40][41][42][43][44][45] Due to its properties such as high selectivity, large substrate domain, and high tolerance to temperature and organic solvents, [46][47][48] CaL-B is well known as a catalyst in the kinetic resolution processes of secondary chiral ethanols, 49 including phenothiazine bearing alcohols allowing the preparation of enantiomerically enriched stereoisomers. [50][51][52] Phenothiazine is considered as a molecular template for the design and development of new agents with biomedical applications 53 such as building blocks for antipsychotic drugs, 54 anti-obesity agents, 55 and antitumor active compounds. 53 Moreover, based on their structural and chemical properties, phenothiazine derivatives are used as sensors in different neurotransmitters, 56 for the detection of Cu 2+ in water, 57 and for Hg 2+ detection in vivo.…”

Synthesis of new optically pure tetrabromobenzotriazole derivatives via lipase-catalyzed transesterification

“…The best results are achieved if a large difference in size of the two substituents next to the hydroxyl-attached carbon occurs within the structure of the alcohol [14]. Many factors have an impact on the results of the reaction: lipase type [15][16][17][18], temperature [19], solvent [20][21][22], water content [23] as well as acyl donor [24,25], changing the reaction enantioselectivity factor E [26] or even reversing enantiopreference of the catalyst [23,27]. An enantioselective resolution of similar compounds has been previously reported [19].…”