122743-18-4Relevant articles and documents
Process development of the Sharpless catalytic asymmetric dihydroxylation reaction to prepare methyl (2R,3S)-2,3-dihydroxy-3-phenylpropionate
Lu, Xinbo,Xu, Zhunle,Yang, Guojun
, p. 575 - 576 (2000)
A typical Sharpless catalytic asymmetric dihydroxylation (ADH) process to make methyl (2R,3S)-2,3-dihydroxy-3 phenylpropionate has been successfully developed. The ADH reaction was exothermic and complete in 2-3 h without affecting the optical purity and
Catalytic asymmetric dihydroxylation of olefins with reusable OsO42- on ion-exchangers: The scope and reactivity using various cooxidants
Choudary, Boyapati M.,Chowdari, Naidu S.,Jyothi, Karangula,Kantam, Mannepalli L.
, p. 5341 - 5349 (2002)
Exchanger-OsO4 catalysts are prepared by an ion-exchange technique using layered double hydroxides and quaternary ammonium salts covalently bound to resin and silica as ion-exchangers. The ion-exchangers with different characteristics and opposite ion selectivities are specially chosen to produce the best heterogeneous catalyst that can operate using the various cooxidants in the asymmetric dihydroxylation reaction. LDH-OsO4 catalysts composed of different compositions are evaluated for the asymmetric dihydroxylation of trans-stilbene. Resin-OsO4 and SiO2-OsO4 designed to overcome the problems associated with LDH-OsO4 indeed show consistent activity and enantioselectivity in asymmetric dihydroxylation of olefins using K3Fe(CN)6 and molecular oxygen as cooxidants. Compared to the Kobayashi heterogeneous systems, resin-OsO4 is a very efficient catalyst for the dihydroxylation of a wide variety of aromatic, aliphatic, acyclic, cyclic, mono-, di-, and trisubstituted olefins to afford chiral vicinal diols with high yields and enantioselectivities irrespective of the cooxidant used. Resin-OsO4 is recovered quantitatively by a simple filtration and reused for a number of cycles with consistent activity. The high binding ability of the heterogeneous osmium catalyst enables the use of an equimolar ratio of ligand to osmium to give excellent enantioselectives in asymmetric dihydroxylation in contrast to the homogeneous osmium system in which excess molar quantities of the expensive chiral ligand to osmium are invariably used. The complexation of the chiral ligand (DHQD)2PHAL, having very large dimension, a prerequisite to obtain higher ee, is possible only with the OsO42- located on the surface of the supports.
Markedly enhanced recyclability of osmium catalyst in asymmetric dihydroxylation reactions by using macroporous resins bearing both residual vinyl groups and quaternary ammonium moieties
Kim, Kwang Jin,Choi, Han Young,Hwang, Soon Ho,Park, Yil Sung,Kwueon, Eun Kyung,Choi, Doo Seong,Song, Choong Eui
, p. 3337 - 3339 (2005)
Markedly enhanced recyclability of osmium catalyst in asymmetric dihydroxylation has been achieved by using osmylated macroporous resins bearing both residual vinyl groups and quaternary ammonium moiety. The Royal Society of Chemistry 2005.
Polymeric cinchona alkaloids for the heterogeneous catalytic asymmetric dihydroxylation of olefins: The influence of the polymer backbone polarity on the compatibility between polymer support and reaction medium
Song,Roh,Lee,Kim
, p. 2687 - 2694 (1995)
Heterogeneous catalytic asymmetric dihydroxylation of olefins using homo- and co-polymeric cinchona alkaloids has been reported. The benzoate type homopolymers 2a,b showed high enantioselectivity in the heterogeneous ADH reactions, but their catalytic eff
Silica gel supported bis-cinchona alkaloid: A highly efficient chiral ligand for heterogeneous asymmetric dihydroxylation of olefins
Song, Choong Eui,Yang, Jung Woon,Ha, Hyun-Joon
, p. 841 - 844 (1997)
Comparable reactivity and enantioselectivity to those in homogeneous solution have been achieved in heterogeneous catalytic asymmetry dihydroxylation (AD) of elefins using a new silica gel supported cinchona alkaloid containing 1,4-bis(9-O-quinyl)phthalaz
Racemic or enantioselective osmium-catalyzed dihydroxylation of olefins under near-neutral conditions
Blumberg, Shawn,Martin, Stephen F.
, p. 7 - 14 (2020/10/08)
K3Fe(CN)6 and NaIO4 serve as catalytic co-oxidants for osmium-catalyzed dihydroxylations that are performed under near-neutral conditions with K2S2O8 as the stoichiometric oxidant and Na2HPO4 as the base. By using either quinuclidine or hydroquinidine 1,4-phthalazinediyl ether [(DHQD)2Phal], good yields of racemic or enantioenriched diols are obtained. This simple, biphasic procedure offers advantages over other neutral dihydroxylation protocols that use N-methylmorpholine oxide as the stoichiometric oxidant, by suppressing the secondary catalytic cycle that leads to reduced enantioselectivities. The utility of the procedure, which is nicely suited for base-labile starting materials or products, is demonstrated by performing the dihydroxylation in the presence of an aliphatic aldehyde moiety.
Highly Enantioselective Iron-Catalyzed cis-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an FeIII-OOH Reactive Intermediate
Zang, Chao,Liu, Yungen,Xu, Zhen-Jiang,Tse, Chun-Wai,Guan, Xiangguo,Wei, Jinhu,Huang, Jie-Sheng,Che, Chi-Ming
supporting information, p. 10253 - 10257 (2016/08/24)
The development of environmentally benign catalysts for highly enantioselective asymmetric cis-dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′-dimethyl-N,N′-bis(2-methyl-8-quinolyl)-cyclohexane-1,2-diamine) as a catalyst, cis-diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2” method is applicable to both (E)-alkenes and terminal alkenes (24 examples >80 % ee, up to 1 g scale). Mechanistic studies, including18O-labeling, UV/Vis, EPR, ESI-MS analyses, and DFT calculations lend evidence for the involvement of chiral FeIII-OOH active species in enantioselective formation of the two C?O bonds.
