Proazaphosphatranes [P(RNCH₂CH₂)₃N,R= Me,i-Pr,i-Bu]

Synthesis and application of new polymer bound catalysts

“…Because l b is considerably easier and cheaper to synthesize than l e or lg, we continued our investigations with lb, which was prepared from commercially available starting materials in a single step as shown When we screened the trifluoroacetate and triflate salts of l b (lc and Id, respectively) in the reaction of aniline with methyl vinyl ketone under the aforementioned conditions, the reactions were quite slow, furnishing product yields of 70% and 72% after 40 h using IC and after 48 h using ld, respectively. We also tested 10 mol % solution concentrations of HNO,, NaNO,, NaNO, in the presence of 15-crown-5, CAN, Bu,N(NO,), 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazoliurn nitrate in this reaction, all of which provided unimpressive yields of 40,32,20,0,30,45 and 50%, respectively, after 40 h. We attribute these poor results to anion-cation interactions that significantly exceed those experienced with the cation in l b wherein the positive charge is very well delocalized among the phosphorus and the four nitrogens as can be represented by the five resonance structures that can be drawn.…”