22539-93-1Relevant articles and documents
Gold N-Heterocyclic Carbene Catalysts for the Hydrofluorination of Alkynes Using Hydrofluoric Acid: Reaction Scope, Mechanistic Studies and the Tracking of Elusive Intermediates
Bédard, Sandrine,Cavallo, Luigi,Falivene, Laura,Gauthier, Rapha?l,Nolan, Steven P.,Paquin, Jean-Fran?ois,Saab, Marina,Tzouras, Nikolaos V.,Van Hecke, Kristof,Zhang, Ziyun
, (2021/12/09)
An efficient and chemoselective methodology deploying gold-N-heterocyclic carbene (NHC) complexes as catalysts in the hydrofluorination of terminal alkynes using aqueous HF has been developed. Mechanistic studies shed light on an in situ generated catalyst, formed by the reaction of Br?nsted basic gold pre-catalysts with HF in water, which exhibits the highest reactivity and chemoselectivity. The catalytic system has a wide alkyl substituted-substrate scope, and stoichiometric as well as catalytic reactions with tailor-designed gold pre-catalysts enable the identification of various gold species involved along the catalytic cycle. Computational studies aid in understanding the chemoselectivity observed through examination of key mechanistic steps for phosphine- and NHC-coordinated gold species bearing the triflate counterion and the elusive key complex bearing a bifluoride counterion.
Hypervalent Iodine as a Terminal Oxidant in Wacker-Type Oxidation of Terminal Olefins to Methyl Ketones
Chaudhari, Dipali A.,Fernandes, Rodney A.
, p. 2113 - 2121 (2016/03/15)
A mimic of the Wacker process for C=O bond formation in terminal olefins can be initiated by a combination of the Pd(II) and hypervalent iodine reagent, Dess-Martin periodinane to generate methyl ketones. This operationally simple and scalable method offers Markovnikov selectivity, has good functional group compatibility, and is mild and high yielding.
Tsuji-Wacker Oxidation of Terminal Olefins using a Palladium-Carbon Nanotube Nanohybrid
Donck, Simon,Gravel, Edmond,Shah, Nimesh,Jawale, Dhanaji V.,Doris, Eric,Namboothiri, Irishi N. N.
, p. 2318 - 2322 (2015/08/11)
Palladium nanoparticles supported on carbon nanotubes were used in the Tsuji-Wacker oxidation. The palladium-based nanohybrid was found to be very active in combination with cuprous chloride for the selective oxidation of terminal olefins into methyl ketones. The co-catalytic system operates under very mild and sustainable conditions (room temperature, atmospheric pressure, low catalyst loading), as opposed to previously reported catalysts, and can be recycled without any loss in activity. Give it a whack: Palladium nanoparticles supported on carbon nanotubes are used in combination with cuprous chloride for the selective Tsuji-Wacker oxidation of terminal olefins into methyl ketones. The co-catalytic system operates under very mild and sustainable conditions and can be recycled without any loss in activity.
Synthesis of methyl ketones from terminal olefins using PdCl 2/CrO3 system mimicking the Wacker process
Fernandes, Rodney A.,Bethi, Venkati
, p. 4760 - 4767 (2014/06/24)
An efficient synthesis of methyl ketones from terminal olefins using PdCl2/CrO3 system mimicking the Wacker process is developed. The method shows good functional groups compatibility, no aldehyde by-products and is operationally simple. CrO3 is the sole oxidant and replaces both Cu-salts and molecular oxygen, traditionally used in this process. The method holds potential for future applications in organic synthesis.
Iron(III) sulfate as terminal oxidant in the synthesis of methyl ketones via wacker oxidation
Fernandes, Rodney A.,Chaudhari, Dipali A.
, p. 5787 - 5793 (2014/07/08)
An efficient and environmentally benign method using Fe(III) sulfate as a terminal oxidant in the synthesis of methyl ketones from terminal olefins via the Wacker process is developed. The methodology offers high selectivity for a Markonikov product, shows good functional group compatibility, involves mild reaction conditions, and is operationally simple. Fe2(SO 4)3 is the sole terminal oxidant in this process. The method holds potential for future applications in organic synthesis.
Greening the Wacker process
Kulkarni, Mukund G.,Shaikh, Yunnus B.,Borhade, Ajit S.,Chavhan, Sanjay W.,Dhondge, Attrimuni P.,Gaikwad, Dnyaneshwar D.,Desai, Mayur P.,Birhade, Deekshaputra R.,Dhatrak, Nagorao R.
supporting information, p. 2293 - 2295 (2013/06/26)
Wacker oxidation of various terminal olefins with Pd0/C- KBrO3, a nontoxic, environmentally benign, and easy to handle catalyst system, was achieved in high isolated yields. The described protocol offers an alternative to the traditional Wacker system which uses CuCl 2 as co-catalyst. The catalyst is reusable while maintaining high activity and selectivity.
Palladium-catalyzed asymmetric quaternary stereocenter formation
Gottumukkala, Aditya L.,Matcha, Kiran,Lutz, Martin,De Vries, Johannes G.,Minnaard, Adriaan J.
, p. 6907 - 6914 (2012/07/01)
An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF 6, and provides products in up to 99 % enantiomeric excess, with good yields. Based on this strategy, (-)-α-cuparenone has been prepared in only two steps. Copyright
Copper(I)-catalyzed asymmetric desymmetrization: Synthesis of five-membered-ring compounds containing all-carbon quaternary stereocenters
Aikawa, Kohsuke,Okamoto, Tatsuya,Mikami, Koichi
supporting information; experimental part, p. 10329 - 10332 (2012/07/30)
A highly stereoselective catalytic alkylation sequence for the synthesis of highly functionalized and versatile five-membered-ring compounds bearing all-carbon quaternary stereocenters was developed. Enantioselective desymmetrization of achiral cyclopentene-1,3-diones was thus executed by chiral Cu-phosphoramidite catalysts. A variety of complicated cyclopentane derivatives can be synthesized with excellent stereoselectivities using a low catalyst loading in a one-pot operation.
Pd(0)/C catalyzed efficient Wacker oxidation of functionalized terminal olefins
Kulkarni, Mukund G.,Bagale, Sharanappa M.,Shinde, Mahadev P.,Gaikwad, Dnyaneshwar D.,Borhade, Ajit S.,Dhondge, Attrimuni P.,Chavhan, Sanjay W.,Shaikh, Yunnus B.,Ningdale, Vijay B.,Desai, Mayur P.,Birhade, Deekshaputra R.
experimental part, p. 2893 - 2894 (2009/09/06)
Wacker oxidation of terminal olefins was carried out at room temperature and atmospheric pressure by using Pd(0)/C in THF/H2O (9:1). Palladium(0)/C was proven to be highly efficient catalyst for the Wacker oxidation of terminal olefins to the corresponding methyl ketones. The catalyst was reusable while maintaining its activity and selectivity to a high degree.
Process for preparing optically active secondary alcohols having nitrogenous or oxygenic functional groups
-
, (2008/06/13)
A process for preparing optically active secondary alcohols of the general formula (3), [wherein R1 is linear lower alkyl, an aromatic ring group, or the like; A is CH2NR2R3 or the like; n is an integer of 0 to 2; and * represents an asymmetric carbon atom] by asymmetrically hydrogenating a ketone compound of the general formula (1) having nitrogenous or oxygen functional group at any of the a-, β- and γ-positions, with selectivity among functional groups by the use of a ruthenium/optically active bidentate phosphine/diamine complex as the catalyst in the presence of hydrogen alone or together with a base. The optically active secondary alcohols obtained by the process are useful as drugs and intermediates for the preparation of drugs.
