The treatment of diselenides with different perfluoroalkyl iodides in the presence of sodium hydroxymethanesulfinate led to perfluoroalkyl selenides in fair to good yields. The reaction between benzyl perfluorooctyl selenide and chlorine, or sulfuryl chloride, gave rise to the corresponding selenyl chloride and represents an easy route to perfluoroalkylselenyl chlorides.

A new and improved synthetic route to an intermediate in the synthesis of the phosphinate ester GSK2248761A is described. In the key step, we describe the first process-scale example of a palladium-catalyzed phosphorus–carbon coupling to give the entire backbone of GSK2248761A in one telescoped stage in 65% average yield on a 68 kg scale. This unusual chemistry enabled the route to be reduced from six chemistry stages to four and eliminated a number of environmentally unfriendly reagents and solvents.

Amidation of indole 2-carboxylate 1 with ammonia gas via the imidazolide 2 gave GSK2248761A API 3, which was in development for the treatment of HIV. Three significant impurities, namely the phosphinic acid 4, the N-acyl urea 8, and the indoloyl carboxamide 6, were formed during the reaction, and the original process was unable to produce API within clinical specification when run at scale. Investigation into the origin, fate, and control of these impurities led to a new process which was able to produce API within clinical specification.