(1S,2S)-Cyclopentane-1,2-diyl-bis(phosphonous dichloride), (1S,2S)-C5H8(PCl2)2 – A Versatile Optically Active Reagent

Chiral bisphosphanes. V. Chloro{rac,trans-1-[chloro(piperidin-1-yl)phosphino]-2-[bis(piperidin-1-yl)phosphino]cyclopentane-P,P'}neopentylplatinum(II) acetone solvate

“…Consistently, the angle between the normals to the two planes defined by the cis-C 1APt---C11 and cis-P1--Pt--P2 fragments, the limiting value of which is 0 ° for square-planar coordination and 90 ° for tetrahedral, amounts to 9.2 °. The P1--Pt~P2 bite angle of 85.39(11) ° is smaller than that of 87.7(1) ° reported earlier for the structurally related complex [(1S,2S)-C5Hs{P(CH3)CsHI5cyclo-(R)}2PtI2], bearing a bis[(cyclooctyl)methylphosphino]-substituted cyclopentane-based chelate ligand (Dahlenburg & Kurth, 1998 (3),4,] is as expected, because a chloro ligand is at the trans position for the shorter one and is known to be a much weaker transinfluencing group than the neopentyl residue which is trans to the longer platinum-to-phosphorus bond.…”

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

“…In the second approach, 10 was first converted to the tetrachloride Cl 2 P((CH 2 ) 14 )PCl 2 ( 12 ) in 94% yield using triphosgene, a standard reagent for the chlorination of phosphorus–hydrogen bonds [ 49 ]. Since a direct reaction with an excess of the Grignard reagent BrMg(CH 2 ) 6 CH=CH 2 would give 11 , a dead end, initial conversion to the bis(borane) adduct 12 ·2BH 3 was envisioned.…”

Gold(i) chloride adducts of 1,3-bis(di-2-pyridylphosphino)propane: synthesis, structural studies and antitumour activity

“…26 An alternative route involved the reduction of the tetraethyl propylene diphosphonate (prepared from Michaelis-Arbuzov condensation of 1,3dibromopropane and triethylphosphite) 27 with LiAlH 4 , followed by chlorination of the resulting 1,3-bis(phosphino)propane. 28 This could be achieved using phosgene, 29,30 but the more efficacious and considerably less toxic triphosgene (OC(OCCl 3 ) 2 ) has been used previously as an alternative 29,31 and in this case provides a clean option, generating Cl 2 P(CH 2 ) 3 PCl 2 in good yield. The d2pypp ligand can be isolated in solid crystalline form as a hydrochloride salt, which is relatively stable to oxidation in solution.…”

“…(b) Alternatively, d2pypp was synthesised by a more convenient procedure involving treatment of 2-pyridyllithium with Cl 2 P(CH 2 ) 3 PCl 2 (prepared by a modification of the published procedures 29,31 ) and isolation in crystalline form as the hydrochloride salt. To a cooled solution (−10 • C) of H 2 P(CH 2 ) 3 PH 2 (4.05 g, 37.5 mmol) in dichloromethane (150 mL), a solution of bis(trichloromethyl)carbonate (14.90 g, 50.2 mmol) in dichloromethane (90 mL) was added dropwise.…”

“…1 H, 31 P and 13 C NMR were identical with literature values. 29 2-Bromopyridine (3.4 mL, 5.5 g, 35 mmol) in diethyl ether (50 mL) was added dropwise over 30 min to a solution of nbutyllithium (1.6 M solution in hexanes, 21.8 mL, 34.9 mmol) in diethyl ether (200 mL) at −40 • C. The mixture was stirred for 2 h then Cl 2 P(CH 2 ) 3 PCl 2 (1.0 mL, 1.63 g, 6.6 mmol) in diethyl ether (25 mL) was added dropwise. After stirring for a further 2 h, the mixture was allowed to warm to −20 • C and was quenched with 2M H 2 SO 4 (50 mL).…”