Sequential Reactions of Alkynes on an Iridium(III) Single Site. Issue 37 (12th June 2017)

• Record Type: Journal Article
• Authors: Giner, Elena A.; Gómez‐Gallego, Mar; Merinero, Alba D.; Casarrubios, Luis; Ramírez de Arellano, Carmen; Sierra, Miguel A.
• Is Part Of: Chemistry. Volume 23:Issue 37(2017)
• Page Start: 8941
• Page End: 8948
• Publication Date: 2017-06-12
• Subjects: BODIPY -- cascade reactions -- iridium complexes -- nucleotides -- selectivity; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201701100
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Sequential insertion of terminal alkynes on Ir III cyclometalated complexes allow the formation of novel metallapolycycles in a controlled and efficient manner. ortho ‐Methylarylethynyl derivatives led to an unprecedented cascade combination of three fundamental processes (C−C bond formation, C(sp 3 )−H activation, and reductive coupling) on a single Ir III center, in a process compatible with functionalized biomolecules and photoactive substrates. The reaction with tert ‐butylacetylene led to a [6, 5, 4]‐polycycle that incorporates an iridacyclobutenylidene in its structure. The sequence is a multicomponent reaction in which the metal not only promotes the different steps but also determines their stereoselectivity. This is an elegant example of the synergy between a metal‐promoting reaction and a symmetry‐defined stereochemistry. Abstract : On your iridacycle ! Cyclometalated half‐sandwich Ir III complexes react with ortho ‐methyl‐substituted aromatic alkynes to form Ir metallacycles resulting from the consecutive assembly of three efficient reactions: C−C bond formation, C(sp 3 )−H activation, and reductive coupling. The reaction is straightforward and allows for the incorporation of biomolecules (purines), photoactive molecules, and hybrid BODIPY–nucleoside derivatives, and as such are potentially useful for bio‐labeling.