New 18-membered tetrakisphosphine macrocycle and its derivatives

Dynamic Covalent Chemistry Approach toward 18-Membered P4N2 Macrocycles and Their Nickel(II) Complexes

“…It indicates the reversibility of P–C and C–N bond formation, interconversion of all components of the dynamic system, and self-correction of the reaction, which characterize the covalent self-assembly of macrocycles according to DCvC principles. In the final reaction mixtures, several intensive signals in the range of −30 to −40 ppm were observed, which are typical for macrocyclic aminomethylphosphines. − The intensity of the signals of byproducts (acyclic aminomethylphosphines or possible 9-membered cycles as products of [1 + 1] cyclocondensation reactions in the range of −24 to −28 ppm) was noticeably lower than that of the macrocyclic product, indicating that the formation of 18-membered macrocycles is more favorable in comparison with other possible products of the condensation reaction.…”

“…28 Furthermore, an 18-membered P 4 N 2 macrocycle was obtained as meso-I isomer from the condensation reaction of 1,4-bis[hydroxymethyl(pyridine-2yl)phosphino]butane and 4-methylbenzylamine. 29 These compounds were the first exceptions for the above-mentioned rule. The behavior of [P 4 N 2 ]-corands in solutions appears to be more complex than expected due to the lability of the P− CH 2 −N fragment.…”

“… Formation of a tetra­phosphonium macrocycle was observed in the tetramerization of 3-(diphenylphosphino)­propanal under acidic conditions . Our previous works clearly demonstrate that the Mannich-like condensation reaction of primary phosphines or secondary bis-phosphines, formaldehyde, and primary or secondary amines and bis-amines can be employed for the selective synthesis of a wide range of macrocyclic aminomethylphosphines, namely [P 2 N 2 ] 2 -cyclophanes, [P 2 N 4 ]-cyclophanes, [P 4 N 2 ]-cryptand, and [P 4 N 2 ]-corands. − Their synthesis, which is accompanied by reversible P–C and C–N bond formation, proceeds with a remarkable stereoselectivity. Thus, in accordance with the main principles of DCvC (reversibility, thermodynamic control, interconversion of molecular components of the dynamic system) in the covalent self-assembly of [P 4 N 2 ]-corands, only one isomer with a preferred configuration of the four endocyclic phosphorus atoms is isolated from the dynamic system containing five possible stereoisomers of [P 4 N 2 ]-corands (Figure ) and [P 2 N]-corands as products of [1 + 1] condensations as well as cyclic and acyclic oligomers…”

“…Unexpectedly, the meso -I isomer of 14-membered P 4 N 2 macrocycles was recently obtained from the reaction mixture of 1,2-bis­(phenylphosphino)­ethane, formaldehyde, and primary amine when a different workup procedure of the reaction mixture was employed, namely crystallization from diethyl ether or ethanol instead of crystallization from DMF . Furthermore, an 18-membered P 4 N 2 macrocycle was obtained as meso -I isomer from the condensation reaction of 1,4-bis­[hydroxymethyl­(pyridine-2-yl)­phosphino]­butane and 4-methylbenzylamine . These compounds were the first exceptions for the above-mentioned rule.…”

Phospha-Mannich reactions of RPH2, R2PH, and R3P

“…72 [346] RSSR -41.5 (C 6 D 6 ) 28 41 [346] RSSR -41.8 (C 6 D 6 ) 29 i-Pr 11 [347] RSSR -30.3 (-) 30 n-Pr 33 [348] SSSS/RRRR -37.7 (C 6 D 6 ) 31 i-Pr 38 [348] SSSS/RRRR -36.2 (C 6 D 6 ) 32 39 [348] SSSS/RRRR -35.8 (C 6 D 6 ) 33 t-Bu 35 [348] RSSR -36.1 (C 6 D 6 ) 34 47 [349] SSSS/RRRR -41.6 (CDCl 3 ) 35 70, [350] 31 [348] RSSR -31.7 (C 6 D 6 ) 36 57 [349,351] RSSR -42.0 (CDCl 3 ) 37 32 [352] RSSR -36.7 (C 6 D 6 ) 38 33 [352] RSSR -36.5 (C 6 D 6 ) 39 35 [352] RSSR -35.8 (C 6 D 6 )…”