187404-39-3Relevant academic research and scientific papers
Oxazaborolidine-mediated reduction of prochiral 2-alkylidene cycloalkanones
Simpson, Alison F.,Szeto, Peter,Lathbury, David C.,Gallagher, Timothy
, p. 673 - 676 (1997)
Asymmetric reduction of enones 1a-g using either a stoichiometric or catalytic amount of oxazaborolidine 3 proceeds to give the synthetically useful allylic cycloalkanols 2a-g in 83-96% e.e.
Ruthenium-catalysed synthesis of chiral exocyclic allylic alcoholsviachemoselective transfer hydrogenation of 2-arylidene cycloalkanones
Zhang, Kaili,Liu, Qixing,He, Renke,Chen, Danyi,Deng, Zhangshuang,Huang, Nianyu,Zhou, Haifeng
supporting information, p. 1628 - 1632 (2021/03/09)
An exclusive asymmetric reduction of C=O bonds of 2-arylidene four-, five-, six-, and seven-membered cycloalkanones has been studied systematically. The asymmetric transfer hydrogenation was performed using a robust and commercially available chiral diamine-derived ruthenium complex as a catalyst and HCOOH/Et3N as a hydrogen source under mild conditions, giving 51 examples of chiral exocyclic allylic alcohols in up to 96% yield and 99% ee. This method was also applicable to the gram-scale synthesis of the active intermediates of the anti-inflammatory loxoprofen and natural product (?)-goniomitine.
Chiral 2-aromatic methylene naphthenic alcohol and asymmetric synthesizing method thereof
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Paragraph 0027-0031, (2019/01/14)
The invention relates to chiral 2-aromatic methylene naphthenic alcohol and an asymmetric synthesizing method thereof. A specific structure of the chiral 2-aromatic methylene naphthenic alcohol is shown as II. According to the method, mono-sulfonyl chiral
A Ferrocene-Based NH-Free Phosphine-Oxazoline Ligand for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones
Wang, Yanzhao,Yang, Guoqiang,Xie, Fang,Zhang, Wanbin
supporting information, p. 6135 - 6139 (2018/09/27)
A new type of ferrocene-based phosphine-oxazoline ligand has been prepared over a few simple steps. An iridium complex of this ligand is air stable and exhibits excellent performance for the asymmetric hydrogenation of simple ketones (up to 98% yield, up to 99% ee, and 20?000 S/C). Exo-α,β-unsaturated cyclic ketones could be regiospecifically hydrogenated to give chiral allylic alcohols with good results. This study indicates that P,N-ligands can also efficiently promote Ir-catalyzed asymmetric hydrogenation without NH-hydrogen-bonding assistance.
Enantioselective reduction of α,β-enones using an oxazaborolidine catalyst generated in situ from a chiral lactam alcohol
Kawanami, Yasuhiro,Mikami, Yudai,Kiguchi, Kazuya,Harauchi, Yuki,Yanagita, Ryo C.
experimental part, p. 1891 - 1894 (2012/01/05)
The oxazaborolidine catalyst prepared in situ from the chiral lactam alcohol 3 and 4-iodophenoxyborane was found to catalyze the enantioselective reduction of α,β-enones at -40 °C with a high level of enantioselectivity of up to 90% ee.
Highly Enantioselective Hydrogenation of α-Arylmethylene Cycloalkanones Catalyzed by Iridium Complexes of Chiral Spiro Aminophosphine Ligands
Xie, Jian-Bo,Xie, Jian-Hua,Liu, Xiao-Yan,Kong, Wei-Ling,Li, Shen,Zhou, Qi-Lin
scheme or table, p. 4538 - 4539 (2010/06/17)
The highly efficient asymmetric hydrogenation of α-arylmethylene cycloalkanones catalyzed by Ir-complexes of chiral spiro aminophosphine ligands was developed, providing chiral exo-cyclic allylic alcohols at high yields with excellent enantioselectivities (up to 97% ee) and high turnover numbers (S/C up to 10,000). This new reaction provided an efficient method for the synthesis of the key intermediate of the active form of the anti-inflammatory loxoprofen.
The palladium-catalyzed aerobic kinetic resolution of secondary alcohols: Reaction development, scope, and applications
Ebner, David C.,Bagdanoff, Jeffrey T.,Ferreira, Eric M.,McFadden, Ryan M.,Caspi, Daniel D.,Trend, Raissa M.,Stoltz, Brian M.
supporting information; experimental part, p. 12978 - 12992 (2010/06/19)
The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23°C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-toexcellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.
One-pot synthesis and resolution of chiral allylic alcohols
Kamal, Ahmed,Sandbhor, Mahendra,Shaik, Ahmad Ali,Sravanthi
, p. 2839 - 2844 (2007/10/03)
Substituted α,β-unsaturated ketones were selectively reduced to the corresponding allylic alcohols under mild reaction conditions. The allylic alcohols thus obtained were kinetically resolved by lipase catalyzed transesterification in the same pot to affo
Microbially-aided preparation of (S)-2-methoxycyclohexanone key intermediate in the synthesis of Sanfetrinem
Fuganti, Claudio,Grasselli, Piero,Mendozza, Monica,Servi, Stefano,Zucchi, Gioia
, p. 2617 - 2624 (2007/10/03)
(S) 2-Methoxycyclohexanone 1, useful intermediate in the synthesis of Sanfetrinem 2, is obtained from (S) α-benzylidene cyclohexanol 4, derived from the ketone 3 through a short sequence involving as key step yeast reduction of the carbonyl group. The (R) enantiomer of 1 is similarly accessible from the (R) enantiomer of 4 obtained either upon Candida lipolytica-mediated reduction of 3 or from (R,S)-4 by porcine pancreatic lipase catalyzed acetylation with vinyl acetate. Also the saturated carbinols 7 and 8, which accompany 4 in the microbial reduction of 3, are converted into 1 through unexceptional steps. Nocardia opaca, Pichia etchelsii and Mucor subtilissimus provide from 3 upon reduction (S)-configurated 4, 7 and 8 possessing moderate-high ee values.
Baker's yeast reduction of arylidenecycloalkanones
Fogliato, Giovanni,Fronza, Giovanni,Fuganti, Claudio,Lanati, Simonetta,Rallo, Roberta,Rigoni, Romina,Servi, Stefano
, p. 10231 - 10240 (2007/10/02)
The baker's yeast reduction of arylidene cycloalkanones 5, 6 and 7 occurs initially through the catalysis of different enzymes to give the saturation of the double bond leading to the saturated ketones 9, 15 and 22 and the carbonyl reduction to the (S) allylic alcohols 8a, 14 and 23, possessing 0.99, 0.85 and 0.66 ee, respectively. The latter act as inhibitors for the carbonyl reducing enzyme thus preventing the further reduction of the saturated ketone. These compounds in the absence of allylic alcohols are further reduced to a mixture of diastereomic saturated (S) alcohols of high-moderate enantiomeric purity. Reduction experiments in D2O indicate that saturation of the double bond of 5 occurs by β re face addition of hydrogen, as shown by the obtainment of 10'.
