Articolo in rivista, 2019, ENG, 10.1002/adsc.201900633

Iron(III)-Catalyzed Hydration of Unactivated Internal Alkynes in Weak Acidic Medium, under Lewis Acid-Assisted Bronsted Acid Catalysis

Antenucci, Achille; Flamini, Piergiorgio; Fornaiolo, Marco Valerio; Di Silvio, Sergio; Mazzetti, Sara; Mencarelli, Paolo; Salvio, Riccardo; Bassetti, Mauro

Dipartimento di Chimica, Universita? di Roma La Sapienza, P.le A. Moro 5, 00185 Roma, Italy CNR, Istituto per i Sistemi Biologici, Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Universita? La Sapienza, P. le A. Moro 5, 00185 Roma, Italy E-mail: mauro.bassetti@cnr.it Dipartimento di Scienze e Tecnologie Chimiche, Universita? "Tor Vergata", Via della Ricerca Scientifica 1, 00133 Roma, Italy

Alkylarylalkynes are converted with full regioselectivity into the corresponding arylketones by formal hydration of the triple bond under weak acidic conditions, at times and temperatures (<= 95 degrees C) comparable to those used for terminal alkynes. The process catalyzed by Fe-2(SO4)(3)nH(2)O in glacial acetic acid exhibits good functional group compatibility, including that with bulky triple bond substituents, and can be extended to the one-pot transformation of aryltrimethylsilylacetylenes into acetyl derivatives via a desilylation-hydration sequence. The overall reactivity pattern along with proton affinity data indicate that the triple bond is activated by proton transfer rather than by pi-interaction with the metal ion. This mechanistic feature, at variance with that of noble metal catalysts, accounts for the total regioselectivity and the insensitivity to steric hindrance exhibited by the Fe-2(SO4)(3)nH(2)O/AcOH catalytic system.

Advanced synthesis & catalysis (Print) 361 (19), pp. 4517–4526

Keywords

Alkynes, trialkylsilylacetylenes, iron catalysis, protodesilylation, one-pot reactions

CNR authors

Bassetti Mauro

CNR institutes

ISB – Istituto per i Sistemi Biologici

ID: 407887

Year: 2019

Type: Articolo in rivista

Creation: 2019-10-16 10:59:29.000

Last update: 2020-12-07 11:03:14.000

CNR authors

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:407887

DOI: 10.1002/adsc.201900633

ISI Web of Science (WOS): 000481396400001