96010-03-6

Upstream product

• 622-97-9 1-ethenyl-4-methylbenzene 
• 908093-98-1 diazodiphenylmethane 
• 96010-02-5 benzophenone tosylhydrasone sodium salt 
• 119-61-9 benzophenone 
• 5350-57-2 benzophenone hydrazone 

Relevant academic research and scientific papers

Hypervalent-iodine(iii) oxidation of hydrazones to diazo compounds and one-pot nickel(ii)-catalyzed cyclopropanation

A one-pot process for the catalytic cyclopropanation of various alkenes with unsubstituted hydrazones is described. Iodosobenzene (Ph = O) was found to be a competent oxidant of hydrazones to diazo compounds. Ni(OH)2 was chosen as an effective and cheap metal catalyst. The cyclopropane products can be generated efficiently (5 min-4 h) in moderate to good yields (42-91%) under mild (80°C) and neat conditions.

DIKETIMINATO CU(I) AND CO(I) CARBENE CATALYSTS, AND CYCLOPROPANATION METHODS USING THEM

The present invention described herein employs employs Cu(I) complexes of an electron-rich, bidentate N,N-donor ligand (P-diketiminates) that react with both heteroatomcontaining a-substituted diazomethanes and ary1diazomethanes to yield a unique metal-carbene complex stabilized by two metal fragments that selectively reacts with alkenes. These examples are the first of isolable Cu-carbene complexes that react with alkenes to give cyclopropanes. Furthermore, electron-rich, bidentate N,N-donor ligands can be designed to impart stereo- and enantio-selectivity in the cyclopropanation of alkenes with diazoalkanes.

Discrete bridging and terminal copper carbenes in copper-catalyzed cyclopropanation

The Cu(I)/ β-diketiminate [Me2NN]Cu(η2- ethylene) (2) catalyzes the cyclopropanation of styrene with N 2CPh2 to give 1,1,2-triphenylcyclopropane in 67% yield. Addition of N2CPh2 to 2 equiv of 2 allows for the isolation of the dicopper carbene {[Me2NN]Cu}2(μ- CPh2) (3) in which the diphenylcarbene moiety is symmetrically bound between two [Me2NN]Cu fragments (Cu-C = 1,922(4) and 1.930(4) A) with a Cu-Cu separation of 2.4635(7) A. In toluene-d8 solution, 3 reversibly dissociates a [Me2NN]Cu fragment to give [Me2NN]Cu(toluene) and the terminal carbene [Me2NN]Cu= CPh2, Dicopper carbene 3 reacts with 3 equiv of styrene to give 1,1,2-triphenylcyclopropane and 2 equiv of [Me2NN] Cu(η2-styrene) within minutes, DFT studies with simplified ligands indicate a stronger Cu-C π-back-bonding interaction from two Cu(I) centers to the carbene acceptor orbital in a dicopper carbene than that present in a monocopper carbene. Nonetheless, the terminal carbene [Me 3NN]Cu=CPh2 (8) that possesses a p-methyl group on each β-diketiminato N-aryl ring may be isolated and exhibits a shortened Cu-C distance of 1,834(3) A, The stoichiometric cyclopropanation of styrene by 8 in 1,4-dioxane is first-order in both copper carbene 8 and styrene with activation parameters ΔH? = 10,4(3) kcal/mol and ΔS? = -32,3(9) cal/mol·K. In 1,4-dioxane, 8 decomposes to Ph 2C=CPh2 via first-order kinetics with activation parameters ΔH? = 21(1) kcal/mol and ΔS? = -8(3) cal/mol·K. Arene solutions of thermally sensitive terminal carbene 8 decompose to [Me3NN]-Cu(arene), which reacts with 8 still present in solution to give the more thermally stable {[Me3NN]Cu} 2-(μ-CPh2).

Half-sandwich ruthenium(II) complexes of aminophosphines: Synthesis, structures and catalytic applications in C-C coupling reactions between styrenes and diphenyldiazomethane

The half-sandwich Ru(II) complexes of the type [CpRu(PPh2 N(H)R)(PPh3)Cl], [CpRu(PPh2N(H)R)2Cl] (R=Ph, C6H11) and [CpRu(PPh2N(R′) PPh2-κP,κP)(PPh3)]Cl (R′=Et, nPr, iPr, nBu), were synthesized and the structures of complexes [CpRu(PPh2N(H)Ph)(PPh3) Cl] and [CpRu(PPh2N(H)Ph)2Cl] were confirmed by single crystal X-ray diffraction studies. All ruthenium complexes were employed in the cyclopropanation reaction of styrene derivatives in the presence of diphenyldiazomethane. All complexes afford 1,1,3,3-tetraphenyl cyclobutane along with cyclopropane derivatives; complex, [CpRu(PPh2N(nBu)PPh2-κ P,κP) (PPh3)]Cl shows better selectivity in the formation of 1,1,2-triphenylcyclopropane. In all reactions appreciable amounts of cyclopropanation products and metathesis products, 1,2-diphenylcyclopropane and 1,1-diphenylethene were obtained along with 1,1,3-triphenylpropene derivatives. The variable temperature NMR studies have suggested that the cyclopropanation reactions in the presence of ionic complex, [CpRu(PPh2N(R′)PPh 2-κP,κP)(PPh3)]Cl proceeds via carbene intermediate, [CpRu(=CPh2)(PPh2N(R′) PPh2-κP)(PPh3)]Cl.

THE PHILICITY OF A TRIPLET CARBENE: ADDITIONS OF DIPHENYLCARBENE TO STYRENE SUBSTRATES

Triplet diphenylcarbene adds to ring-substituted styrenes as an ambiphile, reacting more rapidly with electron-rich or electron-poor styrenes than with styrene itself.