857198-56-2Relevant academic research and scientific papers
Straightforward formation of carbocations from tertiary carboxylic acids: Via CO release at room temperature
Bartalucci, Niccolò,Pampaloni, Guido,Marchetti, Fabio,Bortoluzzi, Marco,Zacchini, Stefano
, p. 1574 - 1577 (2019)
We report an unprecedented mode of reactivity of carboxylic acids. A series of tertiary carboxylic acids, containing at least one phenyl α-substituent, undergo loss of carbon monoxide at room temperature (295 K), by a one pot reaction with 0.5-1 molar equivalents of WCl6 in dichloromethane. A plausible mechanism for the Ph3CCO2H/WCl6 reaction, leading to [CPh3][WOCl5] and Ph3CCl, is proposed on the basis of DFT calculations. The analogous reactions involving CEt(Ph)2CO2H, CMe(Ph)2CO2H and CMe2(Ph)CO2H selectively afforded stable hydrocarbons (alkene or indene, depending on the case), apparently resulting from the rearrangement of elusive tertiary carbocations.
Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate]: An exceptionally effective Rh(II) catalyst for enantiotopically selective aromatic C-H insertions of diazo ketoesters
Tsutsui, Hideyuki,Yamaguchi, Yukiko,Kitagaki, Shinji,Nakamura, Seiichi,Anada, Masahiro,Hashimoto, Shunichi
, p. 817 - 821 (2007/10/03)
Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2[(S)-TFPTTL]4, in which the phthalimido hydrogen atoms of the parent dirhodium(II) complex are substituted by fluorine atoms, dramatically enhances the reactivity and enantioselectivity (up to 97% ee) in intramolecular aromatic C-H insertion reactions of methyl 4-alkyl-2-diazo-4,4-diphenyl-3-oxopropionates. Catalysis with the use of 0.001 mol% of Rh2[(S)-TFPTTL]4 has achieved the highest turnover number (up to 98,000 with the methyl substituent) ever recorded for chiral dirhodium(II) complex-catalyzed carbene transformations, without compromising the yield or enantioselectivity of the process.
Molecular Modification of Anticholinergics as Probes for Muscarinic Receptors. Amino Esters of α-Substituted Phenylacetic Acid and Related Analogues
Lu, Mattias C.,Wung, Walley E.,Shih, Lisa B.,Callejas, Soledad,Gearien, James E.,Thompson, Emmanuel B.
, p. 273 - 278 (2007/10/02)
Two series of compounds having the general structure of C6H5CRR'COOCH2CH2NEt2 were synthesized and examined for their antispasmodic activities.These compounds were selected as structural probes for exploring the nature of muscarinic cholinergic receptor binding sites that interact with atropine-like anticholinergics.These studies indicate a rather strict size limitation for the hydrophobic region of the receptor and suggest intramolecular hydrogen bonding as a possible means to explain the observed stereoselectivity.
