Reversible Intramolecular P–S Bond Formation Coupled with a Ni(0)/Ni(II) Redox Process

Abstract

P–S bond formation/cleavage mediated by a nickel ion supported by a PPP ligand (PPP = P­[2-P i Pr2-C6H4]2 –) has been investigated herein. To gain an entry into this chemistry, a mononuclear thiolato nickel complex, (PPP)­Ni­(SAr) (1a,b) was prepared by treating the chloride starting material with NaSPh. Upon carbonylation, this complex produces a nickel(0) monocarbonyl species, (PPSArP)­Ni­(CO) (2a,b), in which the thiolate migrates onto the central P of the ligand to give a P–S bond and two-electron reduction of a nickel­(II) center. The reaction undergoes via a pseudo-first-order decay with respect to consumption of a nickel­(II) thiolato species, suggesting an intramolecular reaction under the excess CO­(g) conditions. The reverse reaction involving P–S bond cleavage with concomitant decarbonylation occurs to regenerate 1a,b in benzene. Reaction of 2a with trityl chloride results in Ph3CSPh formation, whereas the reaction with MeI gives methylation at a phosphide moiety or a thiolate group.

Addition of H2 Across a Cobalt–Phosphorus Bond

“…Both stoichiometric and catalytic reactions involving the addition of s bonds across metal-element bonds (element = N, O, C, B, S) have become increasingly prevalent. [25][26][27][28][29][30][31][32] In av ery recent paper by Gudat and coworkers,ametal phosphenium complex, (uNHP Dipp )Mn(CO) 4 (where NHP R indicates amonodentate NHP + cation with N-Rs ubstituents," u" indicates an unsaturated backbone,a nd Dipp = 2,6-diisopropylphenyl), was shown to be an active catalyst for the catalytic dehydrogenation of NH 3 BH 3 . [21][22][23][24] Related examples of metalligand cooperativity involving phosphorus are far less common.…”

“…[21][22][23][24] Related examples of metalligand cooperativity involving phosphorus are far less common. [25][26][27][28][29][30][31][32] In av ery recent paper by Gudat and coworkers,ametal phosphenium complex, (uNHP Dipp )Mn(CO) 4 (where NHP R indicates amonodentate NHP + cation with N-Rs ubstituents," u" indicates an unsaturated backbone,a nd Dipp = 2,6-diisopropylphenyl), was shown to be an active catalyst for the catalytic dehydrogenation of NH 3 BH 3 . (uNHP Dipp -H)Mn(H)(CO) 3 could be generated through sequential addition of ah ydride and ap roton to (uNHP Dipp )Mn(CO) 4 ,and H 2 elimination could be promoted by photolysis;however, direct H 2 addition to (uNHP Dipp )Mn-(CO) 4 was not possible.…”

Solvent-Driven P–S vs P–C Bond Formation from a Diplatinum(III) Complex and Sulfur-Based Anions

“…33,34 Recently, a reversible intramolecular P-S bond formation/cleavage mediated by a Ni(0)/Ni(II) system has been reported. 35 However, to the best of our knowledge, all described cases result in complexes featuring a terminally The IR spectra of complexes 2-5 in the solid state confirm the presence of the relevant ligands and, although they are not particularly informative, it is to note that the band of the C 6 F 5 group which appears at 964 cm -1 for the Pt(III) precursor 1, 9 is shifted toward lower wavelengths in the spectra of 2-5, as consequence of the decrease of the formal oxidation states of the metal centres. 11,37 The 31 P{ 1 H} NMR spectra of 2-5 in deuteroacetone solution showed two broad singlets flanked by 195 Pt satellites.…”

A Nontrigonal Tricoordinate Phosphorus Ligand Exhibiting Reversible “Nonspectator” L/X‐Switching

“…Theproduct was thus assigned to be fluorometallophosphorane 1a F •Fp,i nw hich af luoride has been added to the phosphorus of 1a•Fp + to generate an eutral complex. In solution, compound 1a F •Fp exhibits time-averaged molecular C s -symmetry with ap ersistent P-Feb ond; 13 (3) )that coincides with abathochromic shift of the carbonyl stretching frequencies (n asym = 1952 cm À1 , n sym = 2007 cm À1 ). With respect to the Pbonding environment, metrical parameters give ag eometry index of t = 0.35, indicating ag eometry closer to that of as quare pyramid than at rigonal bipyramid.…”