Nucleophilic substitution reactions of adamantane derivatives with cyclophosphazenes

Investigation of nucleophilic substitution pathway for the reactions of 1,4-benzodioxan-6-amine with chlorocyclophosphazenes

“…These results showed that the substituent effects on bond parameters of P 3 N 3 ring were proportional to the number of substituents on the same phosphorus atom and it could be attributed to electron-releasing character of 1,4-benzodioxan-6-amino groups comparing to withdrawing chlorine substituent [43][44][45]. All of these observations were compatible with the previous studies in the literature [16,20,43,46]. Compounds 7a (2-trans-4) and 7c (2-trans-6) were structural isomers in which the eight-membered cyclotetraphosphazene ring (P 4 N 4 ) was non-geminal bis-substituted with two 1,4-benzodioxan-6-amino-moieties on two sequential phosphorous atoms (P1 and P2) in compound 7a while on two diagonal phosphorous atoms (P1 and P3) in compound 7c (Figs.…”

“…The proton decoupled 31 P NMR spectrum (Fig. 5a) of compound 6 exhibited an A 2 BC type spectrum due to three different phosphorus environments within the molecule as expected [20,24]. Doublet of doublet for PCl 2 groups (d = À5.4 ppm), triplets for PCl 2 group at ca.…”

“…Although the reactions of hexachlorocyclotriphosphazatriene (N 3 P 3 Cl 6 , trimer) with primary aliphatic [15,16] and aromatic [8b, [17][18][19] amines have been studied in great detail [20][21][22][23], there are limited studies about the reactions of octachlorocyclotetraphosphazatetraene (N 4 P 4 Cl 8 , tetramer), with a number of especially primary aromatic amines in the literature [13b, 22,[24][25][26][27]. Because, the reactions of tetramer with amines proceed much faster than that of N 3 P 3 C1 6 [22] due to the skeletal flexibility of the eight-membered ring [22,24] and wealth of product is very high.…”

“…The reactions of the tetramer with primary amines proceed via a non-geminal path up to the replacement of chlorine atoms [15,16,[20][21][22][23][28][29][30][31][32][33][34], whereas the reactions of primary amines with trimer lead to the formation of geminal structures. As the reactions of primary amines progress to higher degrees of substitution, the tri-substituted derivative such as N 3 P 3 C1 3 (NHEt) 3 was not isolated successfully due to low yields.…”

“…The more reactive amines give 2,4-disubstituted product [22,32], the less reactive amines lead to 2,4-and 2,6-derivatives [20][21][22][28][29][30][31][32][33][34].…”