156713-08-5Relevant articles and documents
A Remarkable Inversion in Configuration of the Product Alcohols from the Asymmetric Reduction of ortho-Hydroxyacetophenones with B-Chlorodiisopinocampheylborane
Ramachandran, P. Veeraraghavan,Gong, Baoqing,Brown, Herbert C.
, p. 2141 - 2144 (1994)
Asymmetric reduction of o-hydroxyacetophenones with B-chlorodiisopinocampheylborane provides product alcohols with the opposite configuration compared to those produced in the reduction of the corresponding o-methoxyacetophenones.The implications of this result for organic synthesis are discussed.
P-Stereogenic pincer iridium complexes: Synthesis, structural characterization and application in asymmetric hydrogenation
Yang, Zehua,Wei, Xuan,Liu, Delong,Liu, Yangang,Sugiya, Masashi,Imamoto, Tsuneo,Zhang, Wanbin
, p. 41 - 45 (2015)
P-Stereogenic PNP type pincer iridium complexes PNPtBuMeIrH2Cl (3) and PNPtBuMeIrH3 (4) were synthesized in reasonable yields and characterized by 1H NMR, 13C NMR, 31P NMR, HRMS and/or single crystal X-ray diffraction. The ORTEP diagram shows that the coordination geometry around the iridium center of complex 3 is approximately octahedral. The chlorinated iridium complex (3) and/or the trihydride iridium complex (4) were used as catalysts in the asymmetric hydrogenation of ketones, olefins and quinoline to provide the desired products with up to 17% enantioselectivity.
An Enantioconvergent Benzylic Hydroxylation Using a Chiral Aryl Iodide in a Dual Activation Mode
Abazid, Ayham H.,Clamor, Nils,Nachtsheim, Boris J.
, p. 8042 - 8048 (2020/09/21)
The application of a triazole-substituted chiral iodoarene in a direct enantioselective hydroxylation of alkyl arenes is reported. This method allows the rapid synthesis of chiral benzyl alcohols in high yields and stereocontrol, despite its nontemplated nature. In a cascade activation consisting of an initial irradiation-induced radical C-H-bromination and a consecutive enantioconvergent hydroxylation, the iodoarene catalyst has a dual role. It initiates the radical bromination in its oxidized state through an in-situ-formed bromoiodane and in the second, Cu-catalyzed step, it acts as a chiral ligand. This work demonstrates the ability of a chiral aryl iodide catalyst acting both as an oxidant and as a chiral ligand in a highly enantioselective C-H-activating transformation. Furthermore, this concept presents an enantioconvergent hydroxylation with high selectivity using a synthetic catalyst.
New alkoxymethyl-functionalized pyridinium-based chiral ionic liquids: synthesis, characterization and properties
Gondal, Humaira Yasmeen,Mumtaz, Salma,Abbaskhan, Ahmed,Mumtaz, Nargis,Cano, Israel
, p. 2951 - 2963 (2020/03/23)
Abstract: An efficient solvent-free synthesis of a new family of functionalized chiral ionic liquids based on pyridinium cation has been developed from low-cost chiral terpenoid alcohols. An exhaustive characterization was performed using state-of-the-art
Probing the Effects of Heterocyclic Functionality in [(Benzene)Ru(TsDPENR)Cl] Catalysts for Asymmetric Transfer Hydrogenation
Barrios-Rivera, Jonathan,Xu, Yingjian,Wills, Martin
supporting information, p. 7223 - 7227 (2019/10/08)
A range of TsDPEN catalysts containing heterocyclic groups on the amine nitrogen atom were prepared and evaluated in the asymmetric transfer hydrogenation of ketones. Bidentate and tridentate ligands demonstrated a mutual exclusivity directly related to their function as catalysts. A broad series of ketones were reduced with these new catalysts, permitting the ready identification of an optimal catalyst for each substrate and revealing the subtle effects that changes to nearby donor groups can exhibit.
Water soluble Ru (II)–p-cymene complexes of chiral aroylthiourea ligands derived from unprotected D/L-alanine as proficient catalysts for asymmetric transfer hydrogenation of ketones
Sheeba, Mani Mary,Tamizh, Manoharan Muthu,Bhuvanesh, Nattamai S.P.,Karvembu, Ramasamy
, (2019/01/04)
The newfangled chiral aroylthiourea ligands (L1-L6) were produced from unprotected D/L-alanine and their water soluble Ru (II) organometallic catalysts (1–6) were designed from their reaction with [RuCl2(η6-p-cymene)]2. The analytical and spectral methods were used to confirm the structure of the ligands and complexes. The solid state structure of L1, 5 and 6 was confirmed by single crystal XRD. The organometallic compounds (1–6) catalyzed the asymmetric transfer hydrogenation of aromatic, heteroaromatic and bulky ketones to yield respective enantiopure secondary alcohols with admirable conversions (up to 99%) and attractive enantiomeric excesses (ee up to 98%), in presence of formic acid and triethylamine in water medium under non-inert atmospheric conditions.
CATALYST AND PROCESS FOR SYNTHESISING THE SAME
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Page/Page column 48; 74, (2014/05/24)
The invention relates to a method for synthesising tethered ruthenium catalysts and novel tethered ruthenium catalysts obtainable by this methods. The method involves carrying out an "arene swapping" reaction avoiding the requirement to use complicated techniques making use of unreliable Birch reductions and unstable cyclodienyl intermediates.
Direct formation of tethered Ru(II) catalysts using arene exchange
Soni, Rina,Jolley, Katherine E.,Clarkson, Guy J.,Wills, Martin
supporting information, p. 5110 - 5113 (2013/10/22)
An 'arene exchange' approach has been successfully applied for the first time to the synthesis of Ru(II)-based 'tethered' reduction catalysts directly from their ligands in one step. This provides an alternative method for the formation of known complexes, and a route to a series of novel complexes. The novel complexes are highly active in both asymmetric transfer and pressure hydrogenation of ketones.
Synthesis and application of chiral N,N'-dialkylated cyclohexanediamine for asymmetric hydrogenation of aryl ketones
Ma, Meng Lin,Ren, Chuan Hong,Lv, Ya Jing,Chen, Hua,Li, Xian Jun
scheme or table, p. 155 - 158 (2012/01/03)
Chiral N,N′-dialkylated cyclohexanediamine derived ligands have been synthesized and used in the asymmetric hydrogenation of aryl ketones. Optically active alcohols with up to 90% enantiomeric excess were obtained in high yields.
The stereodivergent asymmetric synthesis of a range of 2-(1′- hydroxyalkyl)phenols
Davies, Stephen G.,Hume, W. Ewan,Roberts, Paul M.,Thomson, James E.
experimental part, p. 8076 - 8088 (2010/10/19)
The use of the (S)-α-methylbenzyl group as a chiral auxiliary has allowed the diastereoselective ortho-deprotonation of a chromium tricarbonyl complexed phenoxy ring. When the resultant ortho-anion is treated with an aldehyde two diastereoisomeric complex
