TMS-ynones

Alonso DA, Najera C, Pacheco MC (2004) Synthesis of ynones by palladium-catalyzed acylation of terminal alkynes with acid chlorides. J Org Chem 69 1615-1619 D Souza DM, Miiller TJJ (2008) Catalytic alkynone generation by Sonogashira reaction and its application in three-component pyrimidine synthesis. Nat Protoc 3 1660-1665 Karpov AS, Miiller TJJ (2003) A new entry to a three component pyrimidine synthesis by TMS-ynones via sonogashira-coupling. Org Lett 5 3451-3454... 

Recently, the coupling of TMSA with heteroaryl carboxylic acid chlorides furnishing TMS-ynones has been reported. Such TMS-ynones resemble versatile synthetic equivalents of p-keto-aldehydes, which can be further elaborated into 2,4-disubstituted pyrimidines (eq 26). 

It is also possible to remove the TMS-group in situ for subsequent conversions. CuCl in 1,3-dimethyl-2-imidazolidinone (DMI) is an effective combination for the direct conversion of TMS-acetylenes and acid halides into ynones (eq 48). Other reagents such as CsOHiCsF (1 1) or InBrs show similar reactivity. 

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