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2,6-Lutidine has been identified as a beneficial additive for the oxidative cleavage of olefins to ketones by NaIO4 in the presence of catalytic RuCl3, improving the yield and shortening the reaction times. In the absence of 2,6-lutidine reactions stalled at the diol intermediate with incomplete conversion to the desired ketones. The reaction protocol described herein also avoids the use of harmful solvents such as CCl4 and DCE and is tolerant of a range of functional groups.

We report a two step one-pot method for the synthesis of 2-bromo-6-aryl[5 H ]pyrrolo[2,3- b ]pyrazines. The process makes use of a cleaner copper-free Sonogashira coupling and an improved base-mediated 5- exo -dig cyclisation to afford the products in good yields. This method expands the scope to structures that are poorly represented in the literature and incorporates a halide for further synthetic elaboration.

The development of a novel palladium-catalysed amidation approach towards 5,7,8,9-tetrahydropyrimido[4,5- b ][1,4]diazepin-6-one templates is highlighted. The route proceeds through the reaction of an amino amide, generated by 1,4-addition of an amine to an acrylamide, with 5-bromo-2,4-dichloropyrimidine and final palladium-catalysed cyclisation to provide the functionalised scaffold in up to 60% isolated yield over three steps. The route offers efficiency advantages over the previously reported nitro-reduction cyclisation approach to these molecules. It also provides alternative means to introduce bulky alkyl substituents at the amide nitrogen. The application of this route in the synthesis of a variety of analogues is described.

A two-step synthesis of 3-(2-chloropyrimidin-4-yl)imidazo[1,2-a]pyridines is presented. The late stage elaboration of the imidazopyridine through a cyclocondensation allows a rapid access to a variety of substitution patterns. The intermediate enol ethers were obtained from inexpensive reagents in a ligand-free Heck coupling. This methodology has been extended to the formation of pyrazolo[1,5-a]pyridines via a formal 1,3-dipolar cycloaddition.