175274-01-8Relevant academic research and scientific papers
C1-Symmetric Binap Derivative Featuring Single Diferrocenylphosphino-Donor Moiety
Enomoto, Yuuki,Ichiryu, Hiroki,Hu, Hao,Ura, Yasuyuki,Ogasawara, Masamichi
supporting information, p. 1020 - 1024 (2021/05/07)
A C1-symmetric chiral bisphosphine, FcPh-Binap (1), which possesses a single diferrocenylphosphino moiety together with a conventional Ph2P-substituent, was prepared in enantiomerically pure forms. Ligand 1 is sterically less demanding than Fc-Segphos (A)
Chiral Bifunctional Phosphine Ligand Enabling Gold-Catalyzed Asymmetric Isomerization of Alkyne to Allene and Asymmetric Synthesis of 2,5-Dihydrofuran
Cheng, Xinpeng,Wang, Zhixun,Quintanilla, Carlos D.,Zhang, Liming
, p. 3787 - 3791 (2019/03/07)
The asymmetric isomerization of alkyne to allene is the most efficient and the completely atom-economic approach to this class of versatile axial chiral structure. However, the state-of-the-art is limited to tert-butyl alk-3-ynoate substrates that possess
Synthesis, Application and Kinetic Studies of Chiral Phosphite-Oxazoline Palladium Complexes as Active and Selective Catalysts in Intermolecular Heck Reactions
Mazloomi, Zahra,Magre, Marc,Del Valle, Efrem,Pericàs, Miquel A.,Pàmies, Oscar,van Leeuwen, Piet W. N. M.,Diéguez, Montserrat
, p. 1650 - 1664 (2018/03/21)
This study identifies new phosphite-oxazoline ligands that have been successfully applied in the palladium-catalyzed intermolecular asymmetric Heck reaction. The design of the new phosphite-oxazoline ligands derives from a previous successful generation of phosphine-oxazoline ligands, by replacing the phosphine group with several π-acceptor biaryl phosphite moieties. With these simple modifications, the new phosphite-based ligands, unlike previous phosphine-oxazoline, not only present a modular design with numerous potential phosphite groups available, but they are also air-stable solids, which can be made in the same number of synthetic steps as the phosphine analogues. The substitution of the phosphine by a biaryl phosphite group extended the range of substrates and triflates sources that can be coupled with regio-, enantioselectivities and activities comparable to the few best ones reported. In addition, the ligands that provided the best selectivities contained an isopropyl oxazoline moiety instead of the tert-butyl group found in the related phosphine-oxazoline ligands, which is made from a much more expensive precursor. In this paper we have also carried out kinetic studies and a Hammett plot analysis to determine the rate determining step of this system in the regime of interest. We suggest a likely explanation for the fast Heck reaction of the phosphite-oxazoline catalysts. (Figure presented.).
Enantioselective synthesis of allenes by catalytic traceless petasis reactions
Jiang, Yao,Diagne, Abdallah B.,Thomson, Regan J.,Schaus, Scott E.
supporting information, p. 1998 - 2005 (2017/02/15)
Allenes are useful functional groups in synthesis as a result of their inherent chemical properties and established reactivity patterns. One property of chemical bonding renders 1,3-substituted allenes chiral, making them attractive targets for asymmetric synthesis. While there are many enantioselective methods to synthesize chiral allenes from chiral starting materials, fewer methods exist to directly synthesize enantioenriched chiral allenes from achiral precursors. We report here an asymmetric boronate addition to sulfonyl hydrazones catalyzed by chiral biphenols to access enantioenriched allenes in a traceless Petasis reaction. The resulting Mannich product from nucleophilic addition eliminates sulfinic acid, yielding a propargylic diazene that performs an alkyne walk to afford the allene. Two enantioselective approaches have been developed; alkynyl boronates add to glycolaldehyde imine to afford allylic hydroxyl allenes, and allyl boronates add to alkynyl imines to form 1,3-alkenyl allenes. In both cases, the products are obtained in high yields and enantioselectivities.
Synthesis, characterization and first application of chiral C2-symmetric bis(phosphinite)-Pd(II) complexes as catalysts in asymmetric intermolecular Heck reactions
Karaka?, Duygu Elma,Durap, Feyyaz,Aydemir, Murat,Baysal, Akin
, p. 193 - 198 (2016/04/05)
A series of new chiral C2-symmetric bis(phosphinite) ligands and their palladium(II) complexes have been synthesized and for the first time used as catalysts in the palladium-catalysed asymmetric intermolecular Heck coupling reactions of 2,3-dihydrofuran with iodobenzene or aryl triflate. Under optimized conditions, products were obtained with high conversions and moderate to good enantioselectivities. The new C2-symmetric bis(phosphinite) ligands and their palladium(II) complexes were characterized using multinuclear NMR and Fourier transform infrared spectroscopies and elemental analysis.
Exploiting the gem-Disubstitution Effect in FcPHOX and HetPHOX P,N Ligands: Synthesis and Applications in Pd-Catalyzed Intermolecular Heck Reactions
McCartney, Dennis,Nottingham, Chris,Müller-Bunz, Helge,Guiry, Patrick J.
, p. 10151 - 10162 (2015/11/03)
The synthesis of a range of novel gem-disubstituted and electronically varied thiophene-oxazoline (HetPHOX) ligands and ferrocene-oxazoline (FcPHOX) ligands and their application in the Pd-catalyzed intermolecular asymmetric Heck reaction (IAH) is described. These investigations show that gem-disubstitution of i-Pr-PHOX-type ligands can lead to effective and cost-efficient alternatives to the corresponding t-Bu-PHOX systems. The Pd complexes of these ligands were very effective in the IAH, providing phenylated products in up to 100% conversion with up to 97% ee.
An emerging reactor technology for chemical synthesis: Surface acoustic wave-assisted closed-vessel Suzuki coupling reactions
Kulkarni, Ketav,Friend, James,Yeo, Leslie,Perlmutter, Patrick
, p. 1305 - 1309 (2014/04/03)
In this paper we demonstrate the use of an energy-efficient surface acoustic wave (SAW) device for driving closed-vessel SAW-assisted (CVSAW), ligand-free Suzuki couplings in aqueous media. The reactions were carried out on a mmolar scale with low to ultr
Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction
Rubina, Marina,Sherrill, William M.,Barkov, Alexey Yu.,Rubin, Michael
, p. 1536 - 1548 (2014/07/22)
A novel class of chiral phosphanyl-oxazoline (PHOX) ligands with a conformationally rigid cyclopropyl backbone was synthesized and tested in the intermolecular asymmetric Heck reaction. Mechanistic modelling and crystallographic studies were used to predict the optimal ligand structure and helped to design a very efficient and highly selective catalytic system. Employment of the optimized ligands in the asymmetric arylation of cyclic olefins allowed for achieving high enantioselectivities and significantly suppressing product isomerization. Factors affecting the selectivity and the rate of the isomerization were identified. It was shown that the nature of this isomerization is different from that demonstrated previously using chiral diphosphine ligands.
Photomechanical actuation of ligand geometry in enantioselective catalysis
Kean, Zachary S.,Akbulatov, Sergey,Tian, Yancong,Widenhoefer, Ross A.,Boulatov, Roman,Craig, Stephen L.
supporting information, p. 14508 - 14511 (2015/02/19)
A catalyst that couples a photoswitch to the biaryl backbone of a chiral bis(phosphine) ligand, thus allowing photochemical manipulation of ligand geometry without perturbing the electronic structure is reported. The changes in catalyst activity and selec
Palladium/sulfoxide-phosphine-catalyzed highly enantioselective allylic etherification and amination
Feng, Bin,Cheng, Hong-Gang,Chen, Jia-Rong,Deng, Qiao-Hui,Lu, Liang-Qiu,Xiao, Wen-Jing
, p. 9550 - 9553 (2014/08/18)
The Pd/sulfoxide-phosphine-catalyzed highly enantioselective allylic etherification and amination with a wide range of O- and N-nucleophiles have been developed (up to 97% yield, 98.5% ee). The products can also be conveniently transformed into biologically active chiral heterocycles. This journal is the Partner Organisations 2014.
