51631-97-1Relevant academic research and scientific papers
Forming All-Carbon Quaternary Stereocenters by Organocatalytic Aminomethylation: Concise Access to β2,2-Amino Acids
Shao, Ying,Sun, Jiangtao,Tang, Shengbiao,Wang, Kai,Yu, Jianliang
supporting information, p. 23516 - 23520 (2020/10/21)
The asymmetric synthesis of β2,2-amino acids remains a formidable challenge in organic synthesis. Here a novel organocatalytic enantioselective aminomethylation of ketenes with stable and readily available N,O-acetals is reported, providing β2,2-amino esters bearing an all-carbon quaternary stereogenic center in high enantiomeric ratios with a catalytic amount of chiral phosphoric acid. Typically, this transformation probably proceeds through an asymmetric counter-anion-directed catalysis. As a result, a concise, practical, and atom-economic protocol toward rapidly access to β2,2-amino acids has been developed.
Palladium-catalyzed α,β-dehydrogenation of acyclic ester equivalents promoted by a novel electron deficient phosphinooxazoline ligand
Fulton, Tyler J.,Wu, Brenda,Alexy, Eric J.,Zhang, Haiming,Stoltz, Brian M.
supporting information, p. 4104 - 4109 (2019/06/20)
A unique example of Pd-catalyzed decarboxylative dehydrogenation of fully substituted N-acyl allyl enol carbonates is enabled by a new electron deficient phosphinooxazoline (PHOX) ligand. The reaction proceeds from the Z-enol carbonate to provide dehydrogenation products exclusively in high E/Z selectivity, while the E-enol carbonate provides the α-allylation product with only minor dehydrogenation. The reaction proceeds with a broad scope of Z-enol carbonates derived from N-acyl indoles to furnish acyclic formal α,β-unsaturated ester equivalents.
Stereo- and Chemodivergent NHC-Promoted Functionalisation of Arylalkylketenes with Chloral
Douglas, James J.,Churchill, Gwydion,Slawin, Alexandra M. Z.,Fox, David J.,Smith, Andrew D.
supporting information, p. 16354 - 16358 (2015/11/09)
Stereo- and chemodivergent enantioselective reaction pathways are observed upon treatment of alkylarylketenes and trichloroacetaldehyde (chloral) with N-heterocyclic carbenes, giving selectively either β-lactones (up to 88:12 dr, up to 94% ee) or α-chloroesters (up to 94% ee). Either 2-arylsubstitution or an α-branched iPr alkyl substituent within the ketene favours the chlorination pathway, allowing chloral to be used as an electrophilic chlorinating reagent in asymmetric catalysis.
Origins of diastereoselectivity in lewis acid promoted ketene-alkene [2 + 2] cycloadditions
Rasik, Christopher M.,Hong, Young J.,Tantillo, Dean J.,Brown, M. Kevin
supporting information, p. 5168 - 5171 (2014/12/11)
A detailed analysis of a Lewis acid promoted ketene-alkene [2 + 2] cycloaddition is reported. The studies have led to a rationalization for an observed inversion of diastereoselectivity between thermally induced and Lewis acid promoted ketene-alkene [2 + 2] cycloadditions. The model is supported with both experimental and computational results.
N-heterocyclic carbene-mediated enantioselective addition of phenols to unsymmetrical alkylarylketenes
Concellon, Carmen,Duguet, Nicolas,Smith, Andrew D.
supporting information; experimental part, p. 3001 - 3009 (2010/03/26)
Chiral N-heterocyclic carbenes (NHCs) mediate the enantioselective addition of 2-phenylphenol to unsymmetrical alkylarylketenes, delivering α-alkyl-α-arylacetic acid derivatives with good levels of enantiocontrol (up to 84% ee). Enantiodivergent stereochemical outcomes are observed using 2-phe-nylphenol and benzhydrol in the NHC-promoted esterification reaction using a triazolium precatalyst derived from pyroglutamic acid, consistent with distinct mechanistic pathways operating within these processes.
Catalytic enantioselective construction of all-carbon quaternary stereocenters: Synthetic and mechanistic studies of the C-acylation of silyl ketene acetals
Mermerian, Ara H.,Fu, Gregory C.
, p. 5604 - 5607 (2007/10/03)
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride → acylpyridinium) and the nucleophile (silyl ketene acetal → enolate).
ARALKYL AMINES AS CANNABINOID RECEPTOR MODULATORS
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Page/Page column 56, (2010/02/11)
Novel compounds of the structural formula (I) are antagonists and/or inverse agonists of the Cannabinoid-1 (CB1) receptor and are useful in the treatment, prevention and suppression of diseases mediated by the CB1 receptor. The compounds of the present invention are useful as centrally acting drugs in the treatment of psychosis, memory deficits, cognitive disorders, migraine, neuropathy, neuro-inflammatory disorders including multiple sclerosis and Guillain-Barre syndrome and the inflammatory sequelae of viral encephalitis, cerebral vascular accidents, and head trauma, anxiety disorders, stress, epilepsy, Parkinson’s disease, movement disorders, and schizophrenia. The compounds are also useful for the treatment of substance abuse disorders, including alcohol and nicotine addiction, the treatment of obesity or eating disorders, as well as the treatment of asthma, constipation, chronic intestinal pseudo-obstruction, and cirrhosis of the liver.
SUBSTITUTED ARYL AMIDES
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Page/Page column 90-91, (2010/02/07)
Novel compounds of structural formula (I) are antagonists and/or inverse agonists of the Cannabinoid-1 (CB1) receptor and are useful in the treatment, prevention and suppression of diseases mediated by the CB1 receptor. The compounds of the present invention are useful as psychotropic drugs in the treatment of psychosis, memory deficits, cognitive disorders, migraine, neuropathy, neuro-inflammatory disorders including multiple sclerosis and Guillain-Barre syndrome and the inflammatory sequelae of viral encephalitis, cerebral vascular accidents, and head trauma, anxiety disorders, stress, epilepsy, Parkinson s disease, movement disorders, and schizophrenia. The compounds are also useful for the treatment of substance abuse disorders, the treatment of obesity or eating disorders, as well as, the treatment of asthma, constipation, chronic intestinal pseudo-obstruction, and cirrhosis of the liver.
Enantioselective staudinger synthesis of β-lactams catalyzed by a planar-chiral nucleophile
Hodous, Brian L.,Fu, Gregory C.
, p. 1578 - 1579 (2007/10/03)
The development of efficient methods for the stereoselective generation of β-lactams is an important goal, due to their biological activity and their utility as synthetic intermediates. The Staudinger reaction, an overall [2 + 2] cycloaddition of a ketene
