Reduction Of Phosphine Oxide And It's Application In Amidation

Organophosphorus compounds are important organic reagents in industrial organic synthesis. For example traditional Wittig, Mitsunobu, Staudinger, Appel reactions, in which triphenylphosphine is used as a coupling agent to promote these reactions. But in the end of these reactions, amounts of triphenylphosphine oxide by-product were produced. Due to the special nature of this by-product, the separation of the product becomes difficult, a large amount of resources was wasted, and a significant negative impact on the environment. And also greatly reduces the atomic utilization of the reaction.To avoid resource waste, we explore a direct application of triphenylphosphine route, the route of the triphenylphosphine oxide used to promote the progress of amidation. On the one hand achieved the reusing of waste, on the other hand the synthesis of amide method of high conversion rate, mild reaction conditions, short reaction time, low cost,the reaction system by-product only CO and CO2, with high atomic efficiency.The reaction process was tracked by 31P NMR, and finally the appropriate reaction mechanism was put forward.In addition, the reduction method of triphenylphosphine oxide was analyzed from the industrial point of view. Finally, the work of this part was divided into two parts.?TMDS as a reducing agent, tetraisopropyl titanium (Ti(O-iPr)4) as a catalyst. Single factor design experiments were designed to optimize the synthesis conditions for obtaining desired yield.?Triphenylphosphine oxide two-step reduction method: oxalyl chloride as activator,triphenylphosphine oxide activated to the corresponding phosphine chloride intermediates,and then by Al/SnCl2 reduction system reduction, in which aluminum powder as a reducing agent, Tin dichloride as catalyst. Single factor design experiments were designed to optimize the synthesis conditions for obtaining desired yield.