sentences:  In place of the halide reagent pseudohalides can also be used, and the coupling has been shown to be quite effective using tosylate and triflate species in variety of conditions.Despite broad success with aryl and vinyl couplings, the use of alkyl halides is less general due to several complicating factors.Having no π-electrons, alkyl halides require different oxidative addition mechanisms than aryl or vinyl groups, and these processes are currently poorly understood.