5668-19-9Relevant academic research and scientific papers
Hydrogen borrowing catalysis using 1° and 2° alcohols: Investigation and scope leading to α and β branched products
Frost, James R.,Cheong, Choon Boon,Akhtar, Wasim M.,Caputo, Dimitri F.J.,Christensen, Kirsten E.,Stevenson, Neil G.,Donohoe, Timothy J.
, (2021/04/07)
The alkylation of a variety of ketones using 1° or 2° alcohols under hydrogen borrowing catalysis is described. Initial research focused on the α-alkylation of cyclopropyl ketones with higher 1° alcohols (i.e. larger than MeOH), leading to the formation of α-branched products. Our search for additional substrates with which to explore this chemistry led us to discover that di-ortho-substituted aryl ketones were also privileged scaffolds, with Ph? (C6Me5) ketones being the optimal choice. Further investigations revealed that this motif was crucial for alkylation with 2° alcohols forming β-branched products, which also provided an opportunity to study diastereoselective and intramolecular hydrogen borrowing processes.
Synthesis and olfactory evaluation of optically active β-alkyl substituted γ-lactones and whiskey lactone analogues
Kato, Daiki,Kawasaki, Masashi,Morita, Yuko,Okada, Takuya,Tanaka, Yasuo,Toyooka, Naoki
, (2020/02/22)
Optically active β-alkyl substituted γ-lactones and whiskey lactone analogues were synthesized, and the odor properties were evaluated. During the preparation of the chiral intermediates, we found good reaction conditions for the highly enantioselective esterification of 3-arylmethyl-2-methyl-1-propanols to kinetically resolve them. The results of the olfactory evaluations of the synthesized lactones revealed that the alkyl groups on the γ-lactone rings played an important role for the odor profiles.
Styrene-acrylic acid synthetic method of the compound
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Paragraph 0030; 0053; 0058; 0059, (2017/05/02)
The invention discloses a method for directly achieving direct arylation reaction of benzene and carbonyl beta-bite sp3C-H bonds employing palladium acetate as a catalyst under the action of bidentate guide base, so as to synthesize a phenylpropionic acid compound. The method comprises the following steps: sequentially adding a 2-propionamido-pyridine-1-oxide, palladium acetate, gibbsite dipotassium phosphate, an aryl iodide compound and dimethylsulfoxide to a shrek tube in an air atmosphere, and reacting for 20-30 hours; after the reaction is ended, cooling to a room temperature, extracting, drying, concentrating and carrying out chromatographic separation to obtain an arylated product; dissolving the obtained arylated product into an ethanol solution of NaOH and reacting for 20-30 hours; and after reaction is ended, neutralizing, extracting, drying, concentrating and carrying out column chromatography to obtain the phenylpropionic acid compound. The method is mild in reaction condition, and good in functional group tolerance; an external additive is not needed; and the carbonyl beta-bite sp3C-H bonds in the 2-propionyl aminopyridine-1-oxide can be directly arylated.
Strategic Application and Transformation of ortho-Disubstituted Phenyl and Cyclopropyl Ketones to Expand the Scope of Hydrogen Borrowing Catalysis
Frost, James R.,Cheong, Choon Boon,Akhtar, Wasim M.,Caputo, Dimitri F. J.,Stevenson, Neil G.,Donohoe, Timothy J.
, p. 15664 - 15667 (2016/01/09)
The application of an iridium-catalyzed hydrogen borrowing process to enable the formation of α-branched ketones with higher alcohols is described. In order to facilitate this reaction, ortho-disubstituted phenyl and cyclopropyl ketones were recognized as crucial structural motifs for C-C bond formation. Having optimized the key catalysis step, the ortho-disubstituted phenyl products could be further manipulated by a retro-Friedel-Crafts acylation reaction to produce synthetically useful carboxylic acid derivatives. In contrast, the cyclopropyl ketones underwent homoconjugate addition with several nucleophiles to provide further functionalized branched ketone products.
Pseudoephenamine: A practical chiral auxiliary for asymmetric synthesis
Morales, Marvin R.,Mellem, Kevin T.,Myers, Andrew G.
supporting information; experimental part, p. 4568 - 4571 (2012/06/30)
Unrestricted: Pseudoephenamine is introduced as a versatile chiral auxiliary and an alternative to pseudoephedrine in asymmetric synthesis. It is free from regulatory restrictions and leads to remarkable stereocontrol in alkylation reactions, especially in those that form quaternary carbon centers. Amides derived from pseudoephenamine exhibit a high propensity to be crystalline substances, and provide sharp, well-defined signals in NMR spectra. Copyright
Structural requirements for substrate in highly enantioselective hydrogenation over the cinchonidine-modified Pd/C
Sugimura, Takashi,Uchida, Takayuki,Watanabe, Junya,Kubota, Takeshi,Okamoto, Yasuaki,Misaki, Tomonori,Okuyama, Tadashi
experimental part, p. 57 - 64 (2009/06/17)
Relationship between substrate structure and enantioselectivity is studied for the asymmetric hydrogenation of 42 different (E)-α, β-disubstituted acrylic acids (propenoic acids) over cinchonidine-modified Pd/C. The β-phenyl group is indispensable for high enantioselectivity of α-phenylcinnamic acid (2,3-diphenylpropenoic acid, 81% ee), and substitution on this group affects markedly the selectivity. The high ee up to 92% was achieved by the β - p-alkoxyphenyl substitution, and the selectivity is ascribed mainly to stronger interaction of the substrate with the chiral modifier on the catalyst surface. In contrast, substitution on the α-phenyl group does not affect notably the enantioselectivity (80-82% ee) or even the α-phenyl group itself is not indispensable but replaceable with a properly bulky group for the high enantioselectivity.
A cleavable linker strategy for optimising enolate alkylation reactions of a polymer-supported Evans' oxazolidin-2-one
Green, Rachel,Merritt, Andrew T.,Bull, Steven D.
, p. 508 - 510 (2008/09/20)
A cleavable linker strategy has been used to optimise the enolate alkylation reactions of a recyclable l-tyrosine derived polymer-supported oxazolidin-2-one for the asymmetric synthesis of a series of chiral α-alkyl acids. The Royal Society of Chemistry.
An easy access to enantio-enriched α-substituted aldehydes by carbolithiation of β-phenyl or β-silyl-α,β-ethylenic aldehydes, protected with the monolithioamide of a chiral diamine
Brémand, Nathalie,Mangeney, Pierre,Normant, Jean F.
, p. 1883 - 1885 (2007/10/03)
Lithium amide derived from N,N,N′-trimethyl-1,2-diphenylethanediamine converts cinnamaldehyde to a lithium alkoxyamide which undergoes a regio- and stereoselective carbolithiation upon addition of various organolithiums. Subsequent hydrolysis or trapping with MeI delivers α-mono-, or α,β-disubstituted 3-phenylpropanals with e.e.s of 76-96%. Extension to a silylated α-enal is possible.
Carbolithiation of an α-amino lithio alkoxide derived from cinnamaldehyde
Brémand, Nathalie,Normant, Jean F.,Mangeney, Pierre
, p. 532 - 534 (2007/10/03)
Cinnamaldehyde adds alkyllithiums on the carbon carbon double bond regioselectively, after protection by the amide of N,N,N' trimethylethanediamine. The benzyllithium reagent thus obtained reacts with electrophiles diastereoselectively.
Structure-based design of ketone-containing, tripeptidyl human rhinovirus 3C protease inhibitors
Dragovich, Peter S.,Zhou, Ru,Webber, Stephen E.,Prins, Thomas J.,Kwok, Annette K.,Okano, Koji,Fuhrman, Shella A.,Zalman, Leora S.,Maldonado, Fausto C.,Brown, Edward L.,Meador III, James W.,Patick, Amy K.,Ford, Clifford E.,Brothers, Mary A.,Binford, Susan L.,Matthews, David A.,Ferre, Rose Ann,Worland, Stephen T.
, p. 45 - 48 (2007/10/03)
Tripeptide-derived molecules incorporating C-terminal ketone electrophiles were evaluated as reversible inhibitors of the cysteine- containing human rhinovirus 3C protease (3CP). An optimized example of such compounds displayed potent 3CP inhibition activ
