212079-68-0Relevant academic research and scientific papers
Unsymmetrical pnp-pincer type phosphaalkene ligands protected by a fused-ring bulky eind group: Synthesis and applications to rh(i) and ir(i) complexes
Taguchi, Hiro-Omi,Sasaki, Daichi,Takeuchi, Katsuhiko,Tsujimoto, Shota,Matsuo, Tsukasa,Tanaka, Hiromasa,Yoshizawa, Kazunari,Ozawa, Fumiyuki
, p. 1526 - 1533 (2016)
We recently reported that 2-(phospholanylmethyl)-6-(2-phosphaethenyl)pyridine (PPEP) with a 2,4,6-tri-tert-butylphenyl group (Mes?) as steric protection of the PC bond serves as a noninnocent ligand on Ir(I), leading to extremely high reactivity toward metal-ligand cooperative activation of ammonia and acetonitrile. The high reactivity is largely due to the strong accepting properties of the PC bond. However, PPEP had a stability problem that provokes the loss of the PC bond on other transition metals, including Rh(I), and restricts its utilization. This paper describes the synthesis of Eind-PPEP protected by an octaethyl-s-hydrindacen-4-yl group (Eind) instead of Mes?. The fused-ring bulky Eind group successfully prevents the loss of the PC bond and enables us to compare the reactivity of Rh(I) and Ir(I) complexes toward ammonia. The complex K[RhCl(Eind-PPEP?)], bearing a dearomatized Eind-PPEP? ligand, undergoes simple ligand displacement to give [Rh(NH3)(Eind-PPEP?)], whereas the iridium analogue K[IrCl(Eind-PPEP?)] causes N-H bond cleavage to form [Ir(NH2)(Eind-PPEP)]. DFT calculations indicate a thermodynamic cause of the metal-dependent product change.
Streamlined Preparation and Coordination Chemistry of Hybrid Phosphine-Phosphaalkene Ligands
Magnuson, Kevin W.,Oshiro, Shelly M.,Gurr, Joshua R.,Yoshida, Wesley Y.,Gembicky, Milan,Rheingold, Arnold L.,Hughes, Russell P.,Cain, Matthew F.
, p. 855 - 859 (2016)
A rationally designed and selective synthesis of hybrid phosphine-phosphaalkene ligands E-1a (Cy2PCH2CH = PMes?, Mes? = 2,4,6-tri-tert-butylphenyl) and E-1b (Ph2PCH2CH = PMes?) was developed using phospha-Wittig methodology. The new hybrid ligands E-1a and E-1b were used to prepare the Pd and Pt dichloride complexes Pd(Cy2PCH2CH = PMes?)Cl2 (2a), Pd(Ph2PCH2CH = PMes?)Cl2 (2b), Pt(Cy2PCH2CH = PMes?)Cl2 (3a), and Pt(Ph2PCH2CH = PMes?)Cl2 (3b). The crystal structures of E-1a, E-1b, 2a·1.33CHCl3, 3a·CH3CN, and 3b were determined. DFT calculations (M06/LACV3PMes??) on 2a revealed that the π? orbital located on the P = C unit is low-lying and accessible. An NBO analysis concluded that the phosphaalkene ligand is a significantly poorer σ donor and a slightly better π acceptor than its tertiary phosphine counterpart, due to the presence of the P = C double bond.
E-Selective Synthesis and Coordination Chemistry of Pyridine-Phosphaalkenes: Five Ligands Produce Four Distinct Types of Ru(II) Complexes
Nakashige, Mika L.,Loristo, Jarin I. P.,Wong, Lesley S.,Gurr, Joshua R.,O'Donnell, Timothy J.,Yoshida, Wesley Y.,Rheingold, Arnold L.,Hughes, Russell P.,Cain, Matthew F.
, p. 3338 - 3348 (2019)
Pyridine-phosphaalkene (PN) ligands 2a-e were prepared in an E-selective fashion using phospha-Wittig methodology. Treatment of these five ligands, varying only in their 6-substituent with RuCl2(PPh3)3, produced four distinct types of coordination complexes: Pyridine-phosphaalkene-derived 3b,d, cyclized 4e, and six-coordinate 5a and 6c. Prolonged heating of 3b,d in THF resulted in C-H activation of the Mes? group and cyclization to give 4b,d featuring a bidentate pyridine-phospholane ligand bound to the metal center. Complex 5a, also possessing a newly formed phospholane ring, contained a different spatial arrangement of donors to Ru(II) with an agostic Ru-H-C interaction serving as the sixth donor to the transition metal center. Ligands 2b,d,e and Ru(II) complexes 3b, 4b,e and 5a were all characterized by X-ray crystallography. Six-coordinate 6c featured a structure similar to 4b,d,e, but with the CF3 substituent acting as a weakly bound sixth ligand to the Ru(II) center, as observed by 31P{1H} and 19F NMR spectroscopy. The calculated structure of 6c established that the closest Ru-a?-a?-F contact was at 2.978 ?.
Synthesis of a Tris(phosphaalkene)phosphine Ligand and Fundamental Organometallic Reactions on Its Sterically Shielded Metal Complexes
Miura-Akagi, Preston M.,Nakashige, Mika L.,Maile, Caitlin K.,Oshiro, Shelly M.,Gurr, Joshua R.,Yoshida, Wesley Y.,Royappa, A. Timothy,Krause, Colleen E.,Rheingold, Arnold L.,Hughes, Russell P.,Cain, Matthew F.
, p. 2224 - 2231 (2016)
A new tris(phosphaalkene)phosphine ligand (1) was synthesized via phospha-Wittig methodology. Metalation of 1 with [RhCl(C2H4)2]2 and [IrCl(COE)2]2 (COE = cyclooctene) produced trigonal bip
Reactivity of phospha-Wittig reagents towards NHCs and NHOs
Gupta, Priyanka,Siewert, Jan-Erik,Wellnitz, Tim,Fischer, Malte,Baumann, Wolgang,Beweries, Torsten,Hering-Junghans, Christian
supporting information, p. 1838 - 1844 (2021/02/16)
Phospha-Wittig reagents, RPPMe3(R = Mes* 2,4,6-tBu3-C6H2;MesTer 2,6-(2,4,6-Me3C6H2)-C6H3;DipTer 2,6-(2,6-iPr2C6H
Phosphaalkenes palladium(II) complexes in the Suzuki and Sonogashira cross-coupling reactions
Deschamps, Bernard,Le Goff, Xavier,Ricard, Louis,Le Floch, Pascal
, p. 363 - 371 (2008/02/12)
The 1-methoxy-2-(supermesitylphos-phanylidenemethyl)-benzene ligand (1) was prepared by reacting the phospha-Wittig reagent [Mes*P=PMe3] with o-methoxybenzaldehyde. Reaction of 1 with one equivalent of the [Pd(allyl)Cl]2 aimer in the presence of Ag(OTf) affords a neutral complex (4) in which the triflate ligand is coordinated to the palladium atom. DFT calculations show that the formation of complex 4 is favored by 22.4 kcal/mol with respect to that of a chelate species involving coordination of the ligand through the phosphorus atom of one lone pair at the oxygen of the pendant methoxy group. Reaction of two equivalents of ligand 1 with the [Pd(allyl)Cl]2 dimer affords complex 5, in which the two ligands are coordinated through their phosphorus atom. The catalytic activity of complex 5 was compared to that of the 1, 3-bis[2-(supermesityl)phosphanediylmethyl]benzene palladium chloride complex (6). Performances of the two catalysts were found to be similar in the Suzuki cross-coupling reaction between phenylboronic acid and some arylbromides (TON between 55.105 and 99.105) as well as in the Sonogashira coupling between phenylacetylene and arylbromides (TON between 400 and 950).
4,6-Bis(supermesitylphosphanylidenemethyl)dibenzofuran. Synthesis, X-ray structure and reactivity towards group 11 metals
Deschamps, Eliane,Deschamps, Bernard,Laure Dormieux, Jeanne,Ricard, Louis,Mezailles, Nicolas,Le Floch, Pascal
, p. 594 - 602 (2007/10/03)
New kinetically stabilized mono- and bis-phosphaalkene ligands (2 and 3, respectively) were synthesized via the phospha-Wittig approach. Ligand 3 was characterized by X-ray diffraction. The coordinating behaviour of the bidentate ligand was investigated t
'Phospha-Wittig' reactions using isolable phosphoranylidenephosphines ArP=PR3 (Ar = 2,6-Mes2C6H3 or 2,4,6-But3C6H2)
Shah, Shashin,Protasiewicz, John D.
, p. 1585 - 1586 (2007/10/03)
Phosphoranylidenephosphines DmpP=PMe3 (1a, Dmp = 2,6-Mes2C6H3) and Mes*P=PMe3 (1b, Mes* = 2,4,6-But3C6H2) act as 'Phospha-Wittig' reagents with aldehydes pr
