1,5-Diaza-3,7-diphosphacyclooctanes

Class of chemical compounds thumb|180 px|P2N2 ligand structure 1,5-Diaza-3,7-diphosphacyclooctanes are organophosphorus compounds with the formula [R'NCH2P(R)CH2]2, often abbreviated PR2NR'2. They are air-sensitive white solids that are soluble in organic solvents. The ligands exist as meso and d,l-diastereomers, but only the meso forms function as bidentate ligands.Synthesis of platinum, palladium and rhodium complexes of α-aminophosphine ligands Erika Bálint Adám Tajti Anna Tripolszky György Keglevich 2018 Dalton Trans. 47 14 4755–4778 10.1039/C8DT00178B 29565437 free10.1021/acs.chemrev.1c01001 Molecular Catalysts with Diphosphine Ligands Containing Pendant Amines 2022 Wiedner Eric S. Appel Aaron M. Raugei Simone Shaw Wendy J. Bullock R. Morris Chemical Reviews 122 14 12427–12474 35640056 249237539 Some metal-PR2NR'2 complexes catalyze the hydrogen evolution reaction as well as the oxidation of hydrogen (H2). The catalytic mechanism involves the interaction of substrate with the amines in the second coordination sphere.Yang J. Y. Chen S. Dougherty W. G. Kassel W. S. Bullock R. M. DuBois D. L. Raugei S. Rousseau R. Dupuis M. Rakowski DuBois M. 34168725 Hydrogen oxidation catalysis by a nickel diphosphine complex with pendant tert-butyl amines Chem. Commun. 46 45 2010 8618–8620 10.1039/c0cc03246h 20938535Bullock R. M. Helm M. L. Molecular Electrocatalysts for Oxidation of Hydrogen Using Earth-Abundant Metals: Shoving Protons Around with Proton Relays Acc. Chem. Res. 2015 48 7 2017–2026 10.1021/acs.accounts.5b00069 26079983 1582563 Synthesis and reactions The ligands are prepared by the condensation of a primary phosphine, formaldehyde, and a primary amine:10.15227/orgsyn.101.0001 free Synthesis of Secondary Benzylic Alcohols by Reductive Arylation of Aldehydes: α-Phenyl-6-quinolinemethanol 2024 t. Thomas Gilian Eric S. Isbrandt Stephen G. Newman Organic Syntheses 101 1–20 2 RPH2 + 4 CH2O + 2 RNH2 → [RNCH2P(R')CH2]2 + 4 H2O Diazadiphosphacyclooctanes function as chelating diphosphine ligands. Typical nickel complexes contain two such ligands are give the formula [Ni(PR2NR'2)2]2+. Cationic complexes of these P2N2 and related ligands often exhibit enhanced reactivity toward H2. These complexes serve as electrocatalysts for H2 evolution. thumb|155px|Conformation of chelate rings in P2N2-M and P2N-M complexes Related ligands Azadiphosphacycloheptanes are a related family of diphosphines, but containing only one amine. They are prepared by condensation of 1,2-bis(phenylphosphino)ethane, formaldehyde, and a primary amine.Karasik A. A. Balueva A. S. Moussina E. I. Naumov R. N. Dobrynin A. B. Krivolapov D. B. Litvinov I. A. Sinyashin O. G. 1,3,6-azadiphosphacycloheptanes: a novel type of heterocyclic diphosphines Heteroatom Chemistry 2008 19 2 125–132 10.1002/hc.20397 From the meso-isomer, typical nickel complexes contain two such ligands, i.e. [Ni(PR2NR')2]2+. When bound to metals, these ligands adopt a conformation similar to that of 1,4-diazacycloheptanes. Acyclic phosphine-amine ligands have the formula (R2PCH2)NR'. References Category:Chelating agents Category:Diphosphines Category:Phosphorus heterocycles Category:Eight-membered rings Category:Meso compounds