For over 30 years the Pd mediated cross-coupling of organostannanes with suitable electrophiles (aka the Stille reaction) has been utilized for the construction of sp²-sp² carbon-carbon bonds. Its continued popularity is in part due to high functional group tolerance, ease of synthetic access to organotin coupling partners, and the ability to control and retain the regio- and stereochemical outcome. Unfortunately, the toxicity of the organotin reagents and tin by-products makes this reaction environmentally unattractive. To alleviate the problems associated with organotin toxicity, including tin handling and dealing with stoichiometric amounts of tin waste, our group developed a one-pot hydrostannation/Stille sequence that is catalytic in tin. Although the process was rendered catalytic, turnover numbers remain modest. Our attempts to improve these turnover numbers have been hampered by a lack of mechanistic understanding of the full role played by the organotins. To gain such insight, we are using ¹¹⁹Sn NMR to monitor the reaction kinetics and elucidate the pathways of the tin species. Recent results and their significance regarding the development of a green Stille reaction will be discussed.