17699-09-1Relevant articles and documents
Influence of a hydroxy group in the asymmetric reduction of selenides: Enantioselective synthesis of naturally occurring monoterpenes
Ceccherelli, Paolo,Curini, Massimo,Epifano, Francesco,Marcotullio, Maria Carla,Rosati, Ornelio
, p. 919 - 922 (1998)
The reductive cleavage of the benzenseleno-group in trans-β- hydroxyselenides, to yield a stereogenic methyne center, has been investigated. When the reaction is carried out with lithium in diethylamine, the equilibrated carbanionic intermediate traps the proton of the neighbouring hydroxy function, blocking the stereogenic center as a product with a predictable chirality. Using this strategy, several natural monoterpenes in enantiomerically pure form have been prepared.
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Sakuda,Y.
, p. 514 - 518 (1961)
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Synthesis of optically active dihydrocarveol via a stepwise or one-pot enzymatic reduction of (R)- and (S)-carvone
Chen, Xi,Gao, Xiuzhen,Wu, Qiaqing,Zhu, Dunming
, p. 734 - 738 (2012)
A recombinant enoate reductase LacER from Lactobacillus casei catalyzed the reduction of (R)-carvone and (S)-carvone to give (2R,5R)-dihydrocarvone and (2R,5S)-dihydrocarvone with 99% and 86% de, respectively, which were further reduced to dihydrocarveols by a carbonyl reductase from Sporobolomyces salmonicolor SSCR or Candida magnolia CMCR. For (R)-carvone, (1S,2R,5R)-dihydrocarveol was produced as the sole product with >99% conversion, while (1S,2R,5S)-dihydrocarveol was obtained as the major product, but with a lower de when (S)-carvone was used as the substrate. The one-pot reduction was performed at a 0.1 M substrate concentration, indicating that it might provide an effective synthetic route to this type of chiral compound.
REDUCTION OF CARBONYL COMPOUNDS VIA HYDROSILYLATION. V. SYNTHESIS OF OPTICALLY ACTIVE ALLYLIC ALCOHOLS VIA REGIOSELECTIVE ASYMMETRIC HYDROSILALATION
Kogure, Tetsuo,Ojima, Iwao
, p. 249 - 256 (1982)
Regioselective asymmetric reduction of prochiral α,β-unsaturated ketones to optically active allylic alcohols was performed via hydrosilylation catalyzed by a rhodium(I) complex with (+)-BMPP, (+)-DIOP and (-)-DIOP as chiral ligands.The allylic alcohols with optical purity up to 69percent e.e. were obtained in good yields.The extent of asymmetric induction was found to depend on the stereoelectronic matching of the chiral ligand, ketone and hydrosilane employed.In the asymmetric reduction of (R)-carbone, leading to carveol, the extent of asymmetric induction was found todepend markedly on the ligand/rhodium ratio.Either trans-(5R,1S)-carveol or cis-(5R,1R)-carveol was obtained with good stereoselectivity by using (-)-DIOP or (+)-DIOP as chiral ligand, and it turned out that the chiral center present in carbone had only a slight influence on the asymmetric induction by the chiral catalysts.
Heterogeneous Hydroxyl-Directed Hydrogenation: Control of Diastereoselectivity through Bimetallic Surface Composition
Shumski, Alexander J.,Swann, William A.,Escorcia, Nicole J.,Li, Christina W.
, p. 6128 - 6134 (2021/05/29)
Directed hydrogenation, in which product selectivity is dictated by the binding of an ancillary directing group on the substrate to the catalyst, is typically catalyzed by homogeneous Rh and Ir complexes. No heterogeneous catalyst has been able to achieve equivalently high directivity due to a lack of control over substrate binding orientation at the catalyst surface. In this work, we demonstrate that Pd-Cu bimetallic nanoparticles with both Pd and Cu atoms distributed across the surface are capable of high conversion and diastereoselectivity in the hydroxyl-directed hydrogenation reaction of terpinen-4-ol. We postulate that the OH directing group adsorbs to the more oxophilic Cu atom while the olefin and hydrogen bind to adjacent Pd atoms, thus enabling selective delivery of hydrogen to the olefin from the same face as the directing group with a 16:1 diastereomeric ratio.
Efficient Transfer Hydrogenation of Ketones using Methanol as Liquid Organic Hydrogen Carrier
Garg, Nidhi,Paira, Soumen,Sundararaju, Basker
, p. 3472 - 3476 (2020/05/29)
Herein, we demonstrate an efficient protocol for transfer hydrogenation of ketones using methanol as practical and useful liquid organic hydrogen carrier (LOHC) under Ir(III) catalysis. Various ketones, including electron-rich/electron-poor aromatic ketones, heteroaromatic and aliphatic ketones, have been efficiently reduced into their corresponding alcohols. Chemoselective reduction of ketones was established in the presence of various other reducible functional groups under mild conditions.
Dihydridoboranes: Selective Reagents for Hydroboration and Hydrodefluorination
Phillips, Nicholas A.,O'hanlon, James,Hooper, Thomas N.,White, Andrew J. P.,Crimmin, Mark R.
supporting information, p. 7289 - 7293 (2019/10/08)
The preparation of a new series of dihydridoboranes supported by N,N-chelating ligands, [R2NCH2CH2NAr]- (R = alkyl, Ar = aryl), is reported. These new boranes react selectively with carbonyls, imines, and a series of electron-deficient fluoroarenes. The reactivity is complementary to recognized reagents such as pinacolborane, catecholborane, NHC-BH3, and borane (BH3) itself. Selectivities are rationalized by invoking both open- A nd closed-chain forms of the reagents as part of equilibrium mixtures.
