7515-24-4Relevant academic research and scientific papers
Organocatalytic trans Phosphinoboration of Internal Alkynes
Fritzemeier, Russell G.,Nekvinda, Jan,Rosenblum, Carol Ann,Santos, Webster L.,Slebodnick, Carla,Vogels, Christopher M.,Westcott, Stephen A.
supporting information, p. 14358 - 14362 (2020/07/04)
We report the first trans phosphinoboration of internal alkynes. With an organophosphine catalyst, alkynoate esters and the phosphinoboronate Ph2P-Bpin are efficiently converted into the corresponding trans-α-phosphino-β-boryl acrylate products in moderate to good yield with high regio- and Z-selectivity. This reaction operates under mild conditions and demonstrates good atom economy, requiring only a modest excess of the phosphinoboronate. X-ray crystallography experiments allowed structural assignment of the unprecedented and densely functionalized (Z)-α-phosphino-β-boryl acrylate products.
Oxidant- and additive-free simple synthesis of 1,1,2-triiodostyrenes by one-pot decaroboxylative iodination of propiolic acids
Ghosh, Subhankar,Ghosh, Rajat,Chattopadhyay, Shital K.
supporting information, (2020/09/15)
A metal- and oxidant-free facile synthesis of a range of 1,1,2-triiodostryrene derivatives has been developed which utilizes a simple decarboxylative triiodination of propiolic acids using molecular iodine and sodium acetate in a one-pot manner. Electron-
Efficient Access to Chiral β-Borylated Carboxylic Esters via Rh-Catalyzed Hydrogenation
Liu, Gang,Li, Anqi,Qin, Xueyuan,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
supporting information, p. 2844 - 2848 (2019/04/26)
Rh/bisphosphine?thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydrogenation of (Z)-β-substituted-β-boryl-α,β-unsaturated esters was successfully developed, furnishing a variety of chiral β-borylated carboxylic esters with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). The gram-scale asymmetric hydrogenation was performed efficiently in the presence of only 0.05 mol% (S/C=2 000) catalyst loading with full conversion, 99% yield and 99% ee. Moreover, the hydrogenation product was easily converted to other versatile synthetic intermediates, such as methyl (S)-3-hydroxy-3-phenylpropanoate and methyl (S)-3-(furan-2-yl)-3-phenylpropanoate. (Figure presented.).
Salt-Free Strategy for the Insertion of CO2 into C?H Bonds: Catalytic Hydroxymethylation of Alkynes
Wendling, Timo,Risto, Eugen,Krause, Thilo,Goo?en, Lukas J.
supporting information, p. 6019 - 6024 (2018/03/27)
A copper(I) catalyst enables the insertion of carbon dioxide into alkyne C?H bonds by using a suitable organic base with which hydrogenation of the resulting carboxylate salt with regeneration of the base becomes thermodynamically feasible. In the presence of catalytic copper(I) chloride/4,7-diphenyl-1,10-phenanthroline, polymer-bound triphenylphosphine, and 2,2,6,6-tetramethylpiperidine as the base, terminal alkynes undergo carboxylation at 15 bar CO2 and room temperature. After filtration, the ammonium alkynecarboxylate can be hydrogenated to the primary alcohol and water at a rhodium/molybdenum catalyst, regenerating the amine base. This demonstrates the feasibility of a salt-free overall process, in which carbon dioxide serves as a C1 building block in a C?H functionalization.
Palladium-Catalyzed Ylidyl-Carbonylation of Aryl Halides to Produce α-Acylphosphoranes
Guo, Xiaojun,Ma, Wei,Xue, Dong,Wang, Chao,Xiao, Jianliang
supporting information, p. 4824 - 4827 (2016/10/14)
An efficient synthesis of α-acylphosphoranes by palladium-catalyzed carbonylation of aryl iodides with carbon monoxide and stabilized phosphonium ylides has been developed. Featuring 44 examples, the protocol displayed a wide substrate scope under mild reaction conditions, showcasing its potential in synthetic organic chemistry.
Application and scope of Schreiber's gold(I)-catalyzed α-pyrone synthesis to ring a aromatic podolactones
Sánchez-Larios, Eduardo,Giacometti, Robert D.,Hanessian, Stephen
supporting information, p. 5664 - 5669 (2014/11/08)
Schreiber's gold(I)-catalyzed synthesis of α-pyrones was adapted to the total synthesis of a ring A aromatic podolactone, urbalactone. The scope of the acetylenic ester partner in the formation of α-pyrones was studied. The total synthesis features, as ke
Pyranone, thiopyranone, and pyridone inhibitors of phosphatidylinositol 3-kinase related kinases. Structure-activity relationships for DNA-dependent protein kinase inhibition, and identification of the first potent and selective inhibitor of the ataxia telangiectasia mutated kinase
Hollick, Jonathan J.,Rigoreau, Laurent J. M.,Cano-Soumillac, Celine,Cockcroft, Xiaoling,Curtin, Nicola J.,Frigerio, Mark,Golding, Bernard T.,Guiard, Sophie,Hardcastle, Ian R.,Hickson, Ian,Hummersone, Marc G.,Menear, Keith A.,Martin, Niall M. B.,Matthews, Ian,Newell, David R.,Ord, Rachel,Richardson, Caroline J.,Smith, Graeme C. M.,Griffin, Roger J.
, p. 1958 - 1972 (2008/02/02)
Structure-activity relationships have been investigated for inhibition of DNA-dependent protein kinase (DNA-PK) and ATM kinase by a series of pyran-2-ones, pyran-4-ones, thiopyran-4-ones, and pyridin-4-ones. A wide range of IC50 values were observed for pyranones and thiopyranones substituted at the 6-position, with the 3- and 5-positions proving intolerant to substitution. Related pyran-2-ones, pyran-4-ones, and thiopyran-4-ones showed similar IC50 values against DNA-PK, whereas the pyridin-4-one system proved, in general, ineffective at inhibiting DNA-PK. Extended libraries exploring the 6-position of 2-morpholinopyran-4-ones and 2-morpholino- thiopyrano-4-ones identified the first highly potent and selective ATM inhibitor 2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one (151C; ATM; IC50 = 13 nM) and revealed constrained SARs for ATM inhibition compared with DNA-PK. One of the most potent DNA-PK inhibitors identified, 2-(4-methoxyphenyl)-6- (morpholin-4-yl)pyran-4-one (16; DNA-PK; IC50 = 220 nM) effectively sensitized HeLa cells to the topoisomerase II inhibitor etoposide in vitro.
Transition-metal-catalyzed carbon-nitrogen and carbon-carbon bond-forming reactions
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Page/Page column 28; Sheet 6, (2008/06/13)
One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in various transition-metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition-metal-catalyzed reactions, including the range of suitable substrates, number of catalyst turnovers, reaction conditions, and efficiency. For example, improvements have been realized in transition metal-catalyzed: aryl amination reactions; aryl amidation reactions; Suzuki couplings; and Sonogashira couplings. In certain embodiments, the invention relates to catalysts and methods of using them that operate in aqueous solvent systems.
General catalysts for the Suzuki-Miyaura and Sonogashira coupling reactions of aryl chlorides and for the coupling of challenging substrate combinations in water
Anderson, Kevin W.,Buchwald, Stephen L.
, p. 6173 - 6177 (2007/10/03)
Amphiphilic phosphine ligands (see structures; Cy = cyclohexyl) were prepared and utilized in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water or water/organic biphasic solvents, providing excellent yields of functionalized b
Preparation of 1-aryl-2-bromo-3,3-difluorocyclopropenes
Lin, Shaw-Tao,Chen, Li-Chwen,Lee, Chun-Jen
, p. 353 - 355 (2007/10/03)
1-Aryl-2-bromo-3,3-difluorocyclopropanes were prepared from the reaction of 2′,2′-difluorostyrene and dibromocarbene instead of from 1-aryl-2-haloacetylenes and difluorocarbene. These results are rationalised by the energy gap between HOMO(styrene), HOMO(acetylene) and LUMO(CX2). The title compounds were converted to methyl arylpropynoate in MeOH solution in quantitative yield.
