Shifting our focus onto α-oxygen carboxylic acids, we found that primary (18 and 19), acyclic secondary (20), and cyclic substrates with various ring sizes (21-23) were all transformed selectively into the C-C coupled products, in addition to an α-sulphur carboxylic acid providing product 29. Cheap and abundant α-amino acids also proved to be excellent coupling partners, transforming protected glycine, alanine, proline, tryptophan, and tyrosine, in addition to two unnatural amino acids, into the corresponding C-C coupled products (24-32). A glycine-alanine dipeptide and a glycine-leucine-threonine tripeptide were also functionalised, demonstrating the extension of the methodology beyond single amino acids (33 and 34). Applying the methodology to substrates bearing no stabilising group alphato the carboxylic acid proved more challenging and in general lower yields were seen under the standard conditions. However, using an increasing amount of acid substrate and base and extended reaction times led to appreciable yields of the desired coupling products. Primary acids, and cyclic secondary acids containing an oxygen or nitrogen heteroatom worked well (35-37). Interestingly, it was possible to transform the acid side chain of both aspartic acid (38) and glutamic acid (39), allowing access to derivatives of phenylalanine and homophenylalanine in a single step, potentially allowing the synthesis of a library of a diverse range of unnatural amino acid derivatives using our methodology. Finally, with the use of acetic acid as a cheap, non-toxic methylating reagent, it was possible to generate methylated product 40 in 23% yield. This route avoids the use of highly electrophilic methylating agents, and could be utilised for the late-stage functionalisation of target molecules in drug discovery campaigns.