i Pr 2 N–P═Fe(CO) 4 in Olefinic Solvents: A Reservoir of a Transient Phosphinidene Complex Capable of Substrate Hopping

Synthesis of 1,1'-bifunctional aminophosphane complexes 3 a-e was achieved by the reaction of Li/Cl phosphinidenoid complex 2 with various primary amines (R=Me, iPr, tBu, Cy, Ph). Deprotonation of complex 3 a (R=Me) with potassium hexamethyldisilazide yielded a mixture of K/NHMe phosphinidenoid complex 4 a and potassium phosphanylamido complex 4 a'. Treatment of complex 3 c (R=tBu) and e (R=Ph) with KHMDS afforded the first examples of K/NHR phosphinidenoid complexes 4 c and e. The reaction of complex 3 c with 2 molar equivalents of KHMDS followed by PhPCl afforded complexes 5 c,c', which possess a P N-ring ligand. All complexes were characterized by NMR, IR, MS, and microanalysis, and additionally, complexes 3 b-e and 5 c' were scrutinized by single-crystal X-ray crystallography.

Section: Resultsmentioning

confidence: 99%

Synthesis and Deprotonation of Aminophosphane Complexes: First K/N(H)R Phosphinidenoid Complexes and Access to a Complex with a P₂N‐Ring Ligand

Majhi

Kyri

Schmer

et al. 2016

“…As has been noted, the chemistry of singlet phosphinidenes with a π‐donating substituent such as RO, R 2 N, R 2 P, with or without coordinated metal, were disclosed at a certain level. However, to the best of our knowledge the only example of an RSP‐type complex was reported by Terlouw, that is, (thiohydroxy)phosphinidene (HSP) .…”

Section: Figurementioning

confidence: 89%

“…Since their discovery by Mathey in 1982, a huge amount of work has been devoted to the chemistry of terminal phosphinidene complexes and their synthetic importance in organophosphorus chemistry has been demonstrated by cycloadditions and bond insertions –. In particular, Lammertsma described a phosphinidene complex [ i Pr 2 NP‐Fe(CO) 4 ], which is stabilized by an amino substituent and effective Fe→P back‐bonding, that undergoes facile and reversible cycloadditions with alkenes and alkynes …”

Section: Figurementioning

confidence: 99%

“…Reversible coordination of low‐valent transition‐metal complexes to alkenes and alkynes is a key step in many catalytic transformations . Phosphinidenes have been proved to display somewhat transition‐metal‐like behavior, such as oxidative addition, reductive elimination, and ligand exchange . To our delight, the tert ‐butylthiophosphinidene complex [ t BuSP‐W(CO) 5 ], which is stabilized by sulfur and coordinated by W(CO) 5 , undergoes facile and reversible cycloadditions with alkenes and alkynes (Scheme ).…”

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

Transition‐Metal‐Like Reversible Cycloadditions of [tBuSP‐W(CO)₅] with Alkenes and Alkynes

Wang

Wei

et al. 2019

tert‐Butylthiophosphinidene complex [tBuSP‐W(CO)5] was generated by dissociation of 1‐(tert‐butylthio)phosphirane–W(CO)5 complex under mild conditions. The formation of transient [tBuSP‐W(CO)5] was indicated by trapping reactions with 2,3‐dimethyl‐1,3‐butadiene, alkynes, phenanthrene‐9,10‐dione, and methanol. The LUMO of [MeSP‐W(CO)5] is significantly lower in energy than those of [Me2NP‐W(CO)5], [MeOP‐W(CO)5], and [Me2PP‐W(CO)5]. The HOMO of [MeSP‐W(CO)5] contains a significant contribution from the in‐plane lone pair of P and the LUMO shows a typical π* characteristic. Since stabilized by sulfur lone pair and coordinated by W(CO)5, [tBuSP‐W(CO)5] undergoes facile and reversible cycloadditions with alkenes and alkynes.

“…Apart from such end‐on adducts to phosphorus, there have been first reports providing evidence for side‐on adducts of π‐systems such as alkenes, carbodiimides or even carbaldehydes as the direct substitution by an NHC derivative suggests. This type of attractive contacts where a pnictogen atom (N, P or As) plays a role as Lewis acid is referred to as pnictogen (or pnicogen) bonding interaction, the electrostatic nature of which has been rationalized on the basis of the Politzer and Murray σ hole concept…”

Section: Introductionmentioning

confidence: 99%

Coordination of N₂ and Other Small Molecules to the Phosphorus Centre of RPW(CO)₅: A Theoretical Study on the Janus Facets of the Stabilization/Activation Problem

Ferao

Streubel

2017

Bonding of neutral terminal phosphinidene tungsten(0) complexes stabilized by ligands bound to phosphorus (ligand-to-P) have been studied using a large testbed of predominantly N-ligands. Most complexes (1 a-r,v-z and 2 l) exhibit a pyramidal P centre with a formal single ligand-to-P bond order. Three ligand-to-P complexes (1 s-u) exhibit planar sp -hybridization of P and P,N bonds featuring double bond character. All derivatives with C-ligands (1 v,x-z) exhibit a ligand-to-P bond strength intermediate between the P-N single and double bonded species. Remarkably, dinuclear complexes containing CN (1 p,w), N (1 r) and N (1-3 t) as bridging ligands between two phosphorus centres show intertwined terminal W(CO) fragments. In particular, the case of N bridging ligand (1-3 t) represents a noteworthy example of activation, displaying a weakened N,N bond and two sets of very strong P,N double bonds, the latter resembling the activation-picture of dinitrogen by transition metal complexes. Bond dissociation energies (BDEs) of ligand-to-P bonds do not show any correlation with a range of bond strength descriptors, but display some meaningful, roughly linear variation with the ligand softness. Based on Haaland's definition of dative bonding, a reasonable linear correlation of BDE with dativity (d ) and the dative covalence energy (DCE ) was found. A moderate correlation was also obtained with the vertical ionization potential of the ligand (I(L)) as well as with the ligands HOMO energy.