752987-39-6

Upstream product

• 592-41-6 1-hexene 
• 53356-73-3 dichloro(2,4,6-tri-isopropylphenyl)phosphane 
• 109-99-9 tetrahydrofuran 
• 41823-71-6 bis(trimethylsilyl)methyllithium 
• 1332877-12-9 mer,cis-(1,8-bis(4′,4′-dimethyloxazolin-2′-yl)-3,6-di-tert-butylcarbazole)YbCl2(tetrahydrofuran) 
• 112438-22-9 (2,4,6-triisopropylphenyl)phosphine 

Relevant academic research and scientific papers

Reactions of Low-Coordinate Cobalt(0)-N-Heterocyclic Carbene Complexes with Primary Aryl Phosphines

Aiming to get knowledge on the reactivity of low-coordinate cobalt(0) species toward primary phosphines, the reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] (IPr = 1,3-bis(2′,6′-diisopropylphenyl)imidazol-2-ylidene, ICy = 1,3-dicyclohexylimidazol-2-ylidene, and vtms = vinyltrimethylsilane) with several primary aryl phosphines have been examined. The reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] with H2PDmp (Dmp = 2,6-dimesitylphenyl) at 80 °C furnish the diamagnetic cobalt(I) phosphido complexes [(NHC)Co(PHDmp)] (NHC = IPr, 1; ICy, 2) that feature the Co-(η6-mesityl) interaction. Complex 1 can coordinate CO to generate the terminal phosphido complex [(IPr)Co(CO)3(PHDmp)] (3) and can be oxidized by [Cp2Fe][BArF4] to yield the cobalt(II) phosphido complex [(IPr)Co(PHDmp)][BArF4] (4, BArF4 = tetrakis(3,5-di(trifluoromethyl)phenyl)borate). For the reactions with sterically less-hindered primary phosphines, [(IPr)Co(vtms)2] is inert toward H2PC6H2-2,4,6-Me3 (H2PMes) at room temperature, whereas [(ICy)2Co(vtms)] can react with H2PMes at room temperature to produce the cobalt(II) phosphido alkyl complex trans-[(ICy)2Co(CH2CH2SiMe3)(PHMes)] (5). At 80 °C, the cobalt(0) alkene complexes [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] and also the cobalt phosphido complexes, 1, 2, and 5 can serve as precatalysts for the dehydrocoupling reaction of H2PMes to afford MesHPPHMes. NHC-Co(I)-phosphido species are proposed as the in-cycle intermediates for these cobalt-catalyzed dehydrocoupling reactions.

Rhodium-Catalyzed Isomerization of a Bis(secondary phosphine) to an Unsymmetrical Diphosphine via P-C Cleavage and P-P and C-H Bond Formation

To develop Rh-catalyzed dehydrocoupling for stereocontrolled synthesis of P-P bonds, we prepared potential intermediates, chiral rhodium phosphine-phosphido complexes, and investigated their stoichiometric and catalytic transformations. Treatment of [Rh(diphos)(COD)][X] with the bis(secondary phosphine) IsHPCH2PHIs (1, Is = 2,4,6-(i-Pr)3C6H2) gave the cations [Rh(diphos)(IsHPCH2PHIs)][X] (diphos? = (R,R)-Me-DuPhos (2), (R,R)-i-Pr-DuPhos (3), or (R,R)-Me-BPE (4); X = BF4 or OTf) with high diastereoselectivity as single C2-symmetric diastereomers. Deprotonation of 2-4 with NaN(SiMe3)2 yielded phosphine-phosphido chelates Rh(diphos)(IsHPCH2PIs) 5-7 with high diastereoselectivity. Thermolysis of 5-7 in toluene at 90 °C caused isomerization to give Rh(diphos)(IsMeP-PIs) (8-10) as mixtures of diastereomers. Under catalytic conditions, Rh-DuPhos precursors slowly converted 1 to a mixture of diastereomers of its isomer, the unsymmetrical diphosphine IsHP-PMeIs (12). We propose a possible mechanism for the isomerization and discuss its relationship to dehydrocoupling catalysis.

Unusual redox chemistry of ytterbium carbazole-bis(oxazoline) compounds: Oxidative coupling of primary phosphines by an ytterbium carbazole- bis(oxazoline) dialkyl

The 1,8-bis(4′,4′-dimethyloxazolin-2′-yl)-3,6-di-tert- butylcarbazole anion (Czx) forms monomeric, six-coordinate halide complexes of Yb(II), (Czx)Yb(X)(THF)2 (X = I (2), Cl (3)), by metathesis of YbX2 with NaCzx (1) or Na/Hg reduction of (Czx)Yb(Cl) 2(THF). The crystal structure of 1 reveals a polymeric chain structure in which the oxazoline ring bridges to the Na+ of an adjacent unit. The iodo complex 2 serves as a precursor to divalent silylamide, alkyl, and phosphide complexes, (Czx)Yb(X)(THF)n (4, X = N(SiMe 3)2, n = 1; 5, X = CH(SiMe3)2, n = 1; 7a, X = 2,4,6-Me3C6H2PH, n = 2; 7b, X = 2,4,6-Pri3C6H2PH, n = 2). The X-ray structure of 4 reveals a distorted-trigonal-bipyramidal geometry with the Czx ligand occupying two axial sites and one equatorial site in a pseudo-mer coordination mode. In contrast to the typical metathesis chemistry observed with LiCH(SiMe3)2, an unusual oxidation occurs when 2 or 3 is treated with LiCH2SiMe3 to generate the previously isolated trivalent alkyl (Czx)Yb(CH2SiMe3)2. Trivalent Yb complexes with the Czx ligand also display unusual redox chemistry: rapid reduction to the Yb(II) phosphides 7a,b is observed on treatment of mer,cis-(Czx)Yb(Cl)2(THF) with ArPH- Na+ (6a,b) or, equivalently, on treatment of (Czx)Yb(CH2SiMe3) 2 with ArPH2. In both cases, oxidative coupling of the phosphide or phosphine was observed to form meso- and rac-biphosphines, ArPH-PHAr (Ar = 2,4,6-Me3C6H2 (9a), 2,4,6-Pri3C6H2 (9b)).

Electrocatalytic reduction of aryldichlorophosphines with the (2,2′-bipyridine)nickel complexes

The reduction of aryldichlorophosphines in organic solvents was studied by cyclic voltammetry, preparative electrolysis, and chemical reduction. The reaction of the electrochemically generated (2,2′-bipyridine)nickel(0) complexes with aryldichlorophosphines PhPCl2 and tippPCl2 (tipp is 2,4,6-triisopropylphenyl) proceeds through the formation of highly reactive organophosphorus intermediates, whose reactions with diphenylacetylene and hex-1-ene afford phosphirene and phosphirane heterocycles, respectively.