Finally, we identified several species by GC-MS of the reaction mixtures that were invisible to the LC-MS method (Figure , bottom right). These include the expected by-product phenyl isocyanate 20a, azobenzene 21a from oxidative coupling of aniline, which is likely promoted by Pd nanoparticles, hydrolysis product 22a and bi-and terphenyls 23, 24 and 25. Whilst these species were not included in the profiling of reaction from our HTE work vide infra, their presence confirms the high degree of complexity of the reaction under study. Moreover, the identification of these species via GC-MS, but not LC-MS highlights that the sole use of one analysis method (which is commonplace in HTE reaction screening) ought to be viewed with some caution.