20895-62-9

Upstream product

• 74-96-4 ethyl bromide 
• 579-07-7 1-Phenylpropane-1,2-dione 
• 600-14-6 2,3-Pentanedione 
• 934-56-5 trimethyl(phenyl)stannane 
• 88445-06-1 3-phenyl-1-pentyn-3-ol 
• 93-55-0 1-phenyl-propan-1-one 
• 936231-45-7 1-(2-methyl-[1,3]dithian-2-yl)-1-phenyl-propan-1-ol 

Downstream Products

• 936231-22-0 5-ethyl-4-oxo-5-phenyl-4,5-dihydro-furan-2-carboxylic acid methyl ester 

Relevant academic research and scientific papers

Analogues of Acifran: Agonists of the high and low affinity niacin receptors, GPR109a and GPR109b

Recently identified GPCRs, GPR109a and GPR109b, the high and low affinity receptors for niacin, may represent good targets for the development of HDL elevating drugs for the treatment of atherosclerosis. Acifran, an agonist of both receptors, has been tested in human subjects, yet until recently very few analogs had been reported. We describe a series of acifran analogs prepared using newly developed synthetic pathways and evaluated as agonists for GPR109a and GPR109b, resulting in identification of compounds with improved activity at these receptors.

Electroreductive acylation of aromatic ketones with acylimidazoles

The intermolecular reductive coupling of aromatic ketones with acylimidazoles was effected by electroreduction in the presence of chlorotrimethylsilane and gave α-trimethylsiloxy ketones and esters. The best result was obtained using Bu4NPF6 as a supporting electrolyte and a Pb cathode in THF. The α-trimethylsiloxy-containing products were transformed to the corresponding α-hydroxy ketones and esters by treatment with TBAF in THF. This method was also effective for the intramolecular reductive coupling of δ- and ε-keto acylimidazoles.

Rhodium-catalyzed addition of arylstannanes to carbon-heteroatom double bond

The addition of arylstannanes to the carbon-heteroatom double bond in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN)2]BF4) was examined. The reactions of aldehydes, α-dicarbonyl compounds, and N-substituted aldimines with the arylstannanes gave corresponding alcohols, α-hydroxy carbonyl compounds, and amines, respectively. An arylrhodium complex generated by the transmetalation with the arylstannane was probably the active catalytic species.

Asymmetric catalysis, 132 Metal-catalyzed enantioselective α-Ketol rearrangements

Promoted by catalytic amounts of transition-metal complexes, the tertiary α-hydroxy ketones 1, 3, 5/6 undergo α-ketol rearrangements to afford equilibrium mixtures of isomers with a reorganization of the carbon skeleton. The range of metal complexes catalyzing the isomerizations is large; the best results were obtained with the catalyst systems NiCl2/ TMEDA, Ni(acac)2, and Ni(acac)2/TMEDA (TMEDA = N,N,N',N'-tetramethyl-1,2-diaminoethane). The catalytic rearrangements were performed at 130 °C in the absence of solvent, with a Ni/ligand/substrate ratio of 1:2:100. The equilibrium composition of the model system 1/2 is 12.5:87:5. The conversion of the achiral substrates 1 and 3 into the chiral products 2 and 4 can be used for kinetic resolution. However, the reverse reactions 2 → 1 and 4 → 3 in the equilibrations narrow the window for asymmetric induction with enantioselective catalysts of the metal component/optically active ligand type. In system 1, the highest enantiomeric excess was achieved with the catalyst systems NiCl2/pybox [18.9% (S)-2] and Ni(acac)2/pybox [19.3% (R)-2] {pybox = 2,6-bis[(S)-4-isopropyl(oxazolin-2'-yl)]pyridine}. The α-ketol rearrangement of 3 with the Ni(acac)2/pybox catalyst resulted in a maximum enantiomeric excess of 37.1% (S)-4.