864286-94-2Relevant academic research and scientific papers
Kinetic resolution of 1-biaryl- and 1-(pyridylphenyl)alkan-1-ols catalysed by the lipase b from Candida antarctica
Kourist, Robert,Gonzalez-Sabin, Javier,Liz, Ramon,Rebolledo, Francisca
, p. 695 - 702 (2005)
Lipase B from Candida antarctica (CAL-B) catalyses the highly enantioselective (E > 200) transesterification of some 1-biaryl-2-yl-, -3-yl-, and -4-yl-ethanols and -propan-1-ols, as well as 1-(o-, m-, and p-pyridylphenyl)ethanols, 6, with vinyl acetate, Kazlauskas' rule being obeyed in all cases, meta and para-Substituted substrates were transformed within several hours (conversion degree ranging from 23-50%), reaction rates for propan-1-ol derivatives being slower than those for ethanol derivatives. Transesterifications of ortho-substituted alcohols took several days and were accompanied by a chemoenzymatic side reaction: the formation of another acetate derived from the hemiacetal between 6 and acetaldehyde coming from vinyl acetate. This side reaction was suppressed in the presence of isopropenyl acetate as acyl donor, conversion degrees for transesterification ranging from 20-40% after ten days (E > 200). The usefulness of (R)-6p as ligand in the asymmetric addition of diethylzinc to benzaldehyde was also demonstrated.
Iridium-Catalyzed Branch-Selective Hydroarylation of Vinyl Ethers via C-H Bond Activation
Ebe, Yusuke,Nishimura, Takahiro
, p. 5899 - 5902 (2015)
Iridium-catalyzed hydroarylation of vinyl ethers via a directed C-H bond activation of aromatic compounds gave high yields of the corresponding addition products with high branch selectivity.
Rh(III)-Catalyzed Regioselective Acetylation of sp2 C?H Bond Starting from Paraformaldehyde
Wan, Ting,Du, Sidong,Pi, Chao,Wang, Yong,Li, Rongbin,Wu, Yangjie,Cui, Xiuling
, p. 3791 - 3796 (2019/02/25)
Rh(III)-catalyzed acetylation of sp2 C?H bonds has been realized using paraformaldehyde as an acetylating reagent. This procedure features simultaneous formation of two C?C bonds, external oxidants free, and water as the sole byproducts, thus offering an environmentally benign acetylation of arenes. A range of functional groups tolerance were observed.
A Straightforward Deracemization of sec-Alcohols Combining Organocatalytic Oxidation and Biocatalytic Reduction
Liardo, Elisa,Ríos-Lombardía, Nicolás,Morís, Francisco,González-Sabín, Javier,Rebolledo, Francisca
supporting information, p. 3031 - 3035 (2018/06/27)
An efficient organocatalytic oxidation of racemic secondary alcohols, mediated by sodium hypochlorite (NaOCl) and 2-azaadamantane N-oxyl (AZADO), has been conveniently coupled with a highly stereoselective bioreduction of the intermediate ketone, catalyzed by ketoreductases, in aqueous medium. The potential of this one-pot two-step deracemization process has been proven by a large set of structurally different secondary alcohols. Reactions were carried out up to 100 mm final concentration enabling the preparation of enantiopure alcohols with very high isolated yields (up to 98 %). When the protocol was applied to the stereoisomeric rac/meso mixture of diols, these were obtained with very high enantiomeric excesses and diastereomeric ratios (95 % yield, >99 % ee, >99: 1 dr).
