Aminolysis of N-phosphorylated pyridines

Biological Phosphoryl-Transfer Reactions: Understanding Mechanism and Catalysis

“…In Figure 5 a,b , experimental LFERs are plotted for reactions of monosubstituted phosphoryl compounds (19, 20, 28, 31–33, 45–47) (see Supplemental Section D for additional data sets). For the hydrolysis reactions of phosphate esters, there is a large sensitivity to leaving group p K a (β LG = –1.26) ( Figure 5 a ).…”

“…To evaluate both β NUC and β LG , we turn to nitrogen nucleophiles and leaving groups ( Figure 5 c ), as more complete data are available for these reactions. Here β LG = –0.95 for reaction of morpholine with phosphorylated pyridines (47), β NUC = 0.16 for reaction of pyridines with 3-methoxypyridine (32), and β EQ has been estimated to be 1.05 ( Figure 5 a,b ) (32). These values correspond to estimated charge changes of |β LG / β EQ = 0.90 and |β NUC / β EQ | = 0.15, suggesting extensive bond cleavage to the leaving group and little bond formation to the nucleophile, i.e., a loose transition state in the lower right corner of the two-dimensional reaction coordinate diagram ( Figure 3 c ).…”

“…In red: hydrolysis reactions of phosphorylated pyridines [ squares (31) and circles (33)]. In blue: morpholine nucleophile reacting with phosphorylated pyridines (47). ( b ) Observed β NUC LFERs.…”

4-Dialkylaminopyridine als hochwirksame Acylierungskatalysatoren

“…Einen Vergleich der nucleophilen Katalyse mehrerer Basen ohne den storenden Einflulj von Solvatation und allgemeiner Basekatalyse ermoglicht die intramolekulare Acylverschiebung bei 5-Acyloxyoxazolen wie ( 1 13), das von zahlreichen Basen B iiber das Ionenpaar (114) Anyen> Chem. 90.…”

Chromogenic, Specific Detection of the Nerve‐Agent Mimic DCNP (a Tabun Mimic)

“…From the literature, it is apparent that both the aniline and pyridine groups can react with phosphates and phosphonates with good leaving groups (e.g., nerve gases) 12. Additionally, phosphorylation reactions of pyridine are known to strongly depend on the phosphorylating agent and are, in some cases, reversible in the presence of nucleophilic species 13. The presence of the nucleophile cyanide (as a sub‐product of the phosphorylation reactions with DCNP) and the possible formation of two different products (see below) are concepts that allowed the design of a colorimetric probe that is able to selectively sense the nerve‐agent‐mimic DCNP (a Tabun mimic).…”