Developments in C-H functionalization: novel metal-catalysed oxidative annulations
Dooley, Johnathon Daniel
MetadataShow full item record
Catalyst-Controlled Divergent C–H Functionalization of Unsymmetrical 2-Aryl Cyclic 1,3-Dicarbonyl Compounds with Alkynes and Alkenes A problem faced within the area of C–H functionalization is achieving siteselectivity when several similar C–H bonds are present within a given compound. One solution to this problem is the development of reactions that employ different catalytic systems to control the required selectivity. Herein, it is shown that such catalyst-controlled selectivity could be achieved on 2-aryl cyclic 1,3-dicarbonyl compounds where there exist two potential, non-adjacent sites for C–H functionalization. Examples demonstrate the palladium- and ruthenium-catalysed oxidative annulations of the 2-aryl cyclic 1,3-dicarbonyl substrates with alkynes, as well as with alkenes, where initial C–H bond cleavage occurs at one of two potential sites, depending on the catalyst used, which give unique products. 1,4-Rhodium(III) Migration in the One-Carbon Oxidative Annulations of 2-Arylphenols, Benzamides, and Benzoic Acids with 1,3-Enynes Oxidative annulations of 2-arylphenols, benzamides, and benzoic acids with alkynes and enynes are precedented and provide a range of heterocyclic products. However, in these examples, either the alkyne or enyne acts as a two-carbon annulation partner, reacting only across the alkynyl moiety. Herein, a more expansive scope of a previously published process in which 1,3-enynes, possessing allylic hydrogen atoms cis to the alkyne, undergo oxidative annulations with the three aforementioned classes of substrates as a one-carbon annulation partner is described. Proposed to occur via the 1,4-migration of a rhodium(III) species, annulated products were formed from a range of 1,3-enynes and substrates possessing a variety of functional groups.