79416-49-2Relevant academic research and scientific papers
Palladium Complexes Bearing Chiral bis(NHC) Chelating Ligands on a Spiro Scaffold: Synthesis, Characterization, and Their Application in the Oxidative Kinetic Resolution of Secondary Alcohols
Zhang, Dao,Yu, Jueqin
, p. 605 - 613 (2020/02/13)
A series of chiral bis-N-heterocyclic carbene ligands H2[(S)-1a-d]X2 (X = Br, I) on a spiro scaffold and their palladium complexes (S)-2a-d and (S)-3a,b were prepared and applied in the enantioselective oxidative kinetic resolution of secondary alcohols. The corresponding alcohols can be obtained in high yields with moderate to excellent ee values.
Synthesis, pH-dependent, and plasma stability of meropenem prodrugs for potential use against drug-resistant tuberculosis
Teitelbaum, Aaron M.,Meissner, Anja,Harding, Ryan A.,Wong, Christopher A.,Aldrich, Courtney C.,Remmel, Rory P.
, p. 5605 - 5617 (2013/09/02)
Meropenem, a broad-spectrum parenteral β-lactam antibiotic, in combination with clavulanate has recently shown efficacy in patients with extensively drug-resistant tuberculosis. As a result of meropenem's short half-life and lack of oral bioavailability, the development of an oral therapy is warranted for TB treatment in underserved countries where chronic parenteral therapy is impractical. To improve the oral absorption of meropenem, several alkyloxycarbonyloxyalkyl ester prodrugs with increased lipophilicity were synthesized and their stability in physiological aqueous solutions and guinea pig as well as human plasma was evaluated. The stability of prodrugs in aqueous solution at pH 6.0 and 7.4 was significantly dependent on the ester promoiety with the major degradation product identified as the parent compound meropenem. However, in simulated gastrointestinal fluid (pH 1.2) the major degradation product identified was ring-opened meropenem with the promoiety still intact, suggesting the gastrointestinal environment may reduce the absorption of meropenem prodrugs in vivo unless administered as an enteric-coated formulation. Additionally, the stability of the most aqueous stable prodrugs in guinea pig or human plasma was short, implying a rapid release of parent meropenem.
Enantioselective oxidation of racemic secondary alcohols catalyzed by chiral Mn(iii)-salen complexes with N-bromosuccinimide as a powerful oxidant
Xu, Daqian,Wang, Shoufeng,Shen, Zhiqiang,Xia, Chungu,Sun, Wei
supporting information, p. 2730 - 2732 (2012/11/07)
We demonstrate an efficient enantioselective oxidation of secondary alcohols catalyzed by Mn(iii)-salen complex using N-bromosuccinimide (NBS) as the oxidant. The new protocol is very efficient for the oxidative kinetic resolution of a variety of secondary alcohols, including ortho-substituted benzylic alcohols. The Royal Society of Chemistry 2012.
Aerobic oxidative kinetic resolution of secondary alcohols with naphthoxide-bound iron(salan) complex
Kunisu, Takashi,Oguma, Takuya,Katsuki, Tsutomu
experimental part, p. 12937 - 12939 (2011/10/02)
The first general method for iron-catalyzed aerobic oxidative kinetic resolution of secondary alcohols was achieved with good to high enantiomeric differentiation (krel = 7-50). Although iron(salan) complex 1 does not catalyze alcohol oxidation, the naphthoxide-bound iron(salan) complex does.
Silylation-based kinetic resolution of monofunctional secondary alcohols
Sheppard, Cody I.,Taylor, Jessica L.,Wiskur, Sheryl L.
supporting information; experimental part, p. 3794 - 3797 (2011/10/02)
The nucleophilic small molecule catalyst (-)-tetramisole was found to catalyze the kinetic resolution of monofunctional secondary alcohols via enantioselective silylation. Optimization of this new methodology allows for selectivity factors up to 25 utilizing commercially available reagents and mild reaction conditions.
Scope of enantioselective Palladium(II)-catalyzed aerobic alcohol oxidations with (-)-sparteine
Mandal, Sunil K.,Jensen, David R.,Pugsley, Jacob S.,Sigman, Matthew S.
, p. 4600 - 4603 (2007/10/03)
Evaluation of the substrate scope for Pd(II)/ (-)-sparteine catalyzed aerobic oxidative kinetic resolution of secondary alcohols is disclosed. An improved system is found with use of tert-butyl alcohol solvent in which benzylic and aliphatic alcohols as well as alcohols containing olefins are effectively oxidatively resolved. For substrates that successfully undergo oxidative kinetic resolution, krel values are generally between 10 and 20. Successful scale-up of various substrates to 10-mmol scale is described. Extension to oxidative desymmetrization of 1,3-meso-diols is successful with enantiomeric excesses ranging from 78 to 85%.
Palladium-catalyzed aerobic oxidative kinetic resolution of alcohols with an achiral exogenous base
Mandal, Sunil K.,Sigman, Matthew S.
, p. 7535 - 7537 (2007/10/03)
Substitution of exogenous (-)-sparteine for a more practical achiral base in the aerobic oxidative kinetic resolution of secondary alcohols is described. Carbonate bases are the most effective of those screened and allow for effective kinetic resolution of benzylic, allylic, and aliphatic substrates. The procedure was also successfully extended to the oxidative desymmetrization of meso diols.
Bacterial oxidation of benzocyloalkenes to yield monol, diol and triol metabolites
Boyd, Derek R.,Sharma, Narain D.,Stevenson, Paul J.,Chima, Jagdeep,Gray, David J.,Dalton, Howard
, p. 3887 - 3890 (2007/10/02)
Benzylic monooxygenation of benzocycloalkenes, 2-4, by enzymes in intact cultures of Pseudomonas putida UV4 yielded exclusively the [R] enantiomers, 6-8, and the derived ketones 10-12; by contrast, biotransformation of benzocyclobutene, 1, yielded both monooxygenation (5 and 9), dioxygenation (13,14 and 15), and trioxygenation (16) products.
