Iron(III)‐Catalyzed Hydration of Unactivated Internal Alkynes in Weak Acidic Medium, under Lewis Acid‐Assisted Brønsted Acid Catalysis. Issue 19 (16th August 2019)

• Record Type: Journal Article
• Authors: Antenucci, Achille; Flamini, Piergiorgio; Fornaiolo, Marco Valerio; Di Silvio, Sergio; Mazzetti, Sara; Mencarelli, Paolo; Salvio, Riccardo; Bassetti, Mauro
• Is Part Of: Advanced synthesis & catalysis. Volume 361:Issue 19(2019)
• Page Start: 4517
• Page End: 4526
• Publication Date: 2019-08-16
• Subjects: Alkynes -- trialkylsilylacetylenes -- iron catalysis -- protodesilylation -- one-pot reactions; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201900633
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: 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 °C) comparable to those used for terminal alkynes. The process catalyzed by Fe2 (SO4 )3 n H2 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 π‐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 Fe2 (SO4 )3 n H2 O/AcOH catalytic system. Abstract :