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 WCl 6 in dichloromethane. A plausible mechanism for the Ph 3 CCO 2 H/WCl 6 reaction, leading to [CPh 3 ][WOCl 5 ] and Ph 3 CCl, is proposed on the basis of DFT calculations. The analogous reactions involving CEt(Ph) 2 CO 2 H, CMe(Ph) 2 CO 2 H and CMe 2 (Ph)CO 2 H selectively afforded stable hydrocarbons (alkene or indene, depending on the case), apparently resulting from the rearrangement of elusive tertiary carbocations.
Straightforward formation of carbocations from tertiary carboxylic acids: Via CO release at room temperature / Bartalucci N.; Bortoluzzi M.; Zacchini S.; Pampaloni G.; Marchetti F.. - In: DALTON TRANSACTIONS. - ISSN 1477-9226. - STAMPA. - 48:5(2019), pp. 1574-1577. [10.1039/c8dt04416c]
Straightforward formation of carbocations from tertiary carboxylic acids: Via CO release at room temperature
Zacchini S.;
2019
Abstract
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 WCl 6 in dichloromethane. A plausible mechanism for the Ph 3 CCO 2 H/WCl 6 reaction, leading to [CPh 3 ][WOCl 5 ] and Ph 3 CCl, is proposed on the basis of DFT calculations. The analogous reactions involving CEt(Ph) 2 CO 2 H, CMe(Ph) 2 CO 2 H and CMe 2 (Ph)CO 2 H selectively afforded stable hydrocarbons (alkene or indene, depending on the case), apparently resulting from the rearrangement of elusive tertiary carbocations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
