Examining the stability of phospha(III)guanidines: Formation of a formamidinium:phosphinate ion-pair and an N-protonated phospha(III)guanidinium chloride

Basicity of N‐(Tetramesityltetraphosphacyclopentylidene)cyclohexylamine: An Unusual Diphospha(III)guanidine Derivative

“…The cyclo ‐P 4 C cores in 2 – 4 have a twisted conformation with a trans arrangement of the mesityl substituents (Figure ). The C–N bond lengths in 2 – 4 range from 1.291(6) to 1.303(3) Å (Table ), which is comparable with that of reported phospha(III)guanidines and their complexes . In (H 1 )BF 4 ( 2 ), the hydrogen bond is short [N1–H1 ··· F1 1.81(5) Å] compared to 3 and 4 [N1–H1 ··· Cl1 2.53(2) Å in 3 ; N1–H1 ··· Cl1 2.57(3) Å in 4 ] which indicates a stronger interaction due to the presence of highly electronegative fluorine in the counteranion.…”

“…On the other hand, this increases the versatility as ligand for metal complexes. The first phospha(III)guanidines were reported in the 1980s and have ever since received only minor attention . Recently, we reported the synthesis of a new type of cyclic hetero‐oligophosphane, namely, N ‐(tetramesityltetraphosphacyclopentylidene)cyclohexylamine cyclo ‐P 4 Mes 4 C(NCy) ( 1 ), which contains a structurally related diphospha(III)guanidine moiety (Figure ).…”

Catalytic bond forming reactions promoted by amidinate, guanidinate and phosphaguanidinate compounds of magnesium

“…21 Peaks for PCy 2 H and CyNvCvNCy are also observed, but believed to be due to the facile cleavage of the P-C bond during sample preparation. 80 Hydroacetylenation of carbodiimides. Ethynylamidines, RCuCC{NR′}{NHR′}, are potentially valuable building blocks to organic compounds containing more complex heterocycles including isoxazoles and pyrazoles.…”

Synthesis of Phosphaguanidines by Hydrophosphination of Carbodiimides with Phosphine Boranes

“…For a proof-of-principle study, conversion of phosphaguanidine 19 to the phosphine oxide 22 was accomplished in nearly quantitative yield by treatment with hydrogen peroxide, while previously reported oxidants such as t -butyl hydrogen peroxide and m CPBA resulted in the formation of multiple oxidation products (Scheme ) …”

“…Surprisingly, treatment of 1 with HBF 4 did not cleave the phosphine borane, and the reaction stopped at the N- protonated phosphaguanidine tetrafluoroborate salt 21 (Scheme ). The structure of 21 was secured by X-ray analysis and showed one of the cyclohexyl groups positioned syn and the second anti to the phosphorus atom of the phosphazene …”