64833-56-3Relevant academic research and scientific papers
Photochemistry of 2,3-Di(1'-naphthyl)oxiranes. Spectral and Kinetic Behaviour of Carbonyl Ylides in Condensed Media
Clark, K. B.,Bhattacharyya, K.,Das, P. K.,Scaiano, J. C.,Schaap, A. P.
, p. 3706 - 3712 (1992)
The photochemistry of cis- and trans-2,3-di(1'-naphthyl)oxiranes (c- and t-1) has been studied by nanosecond laser flash photolysis in fluid solution.Direct photolysis (λexc = 248, 266, 308 nm) produces carbonyl ylides which are characterized by broad, structureless absorption bands in the visible region (450-650 nm, λmax ca. 545) and unusually short lifetimes (14-22 ns) in a variety of solvent systems.Triplet energy transfer to the oxiranes results in formation of naphthalene-like triplets (λmax = 410-420 nm, τT max ca. 540-570) similar to those formed via direct excitation but are longer lived (τ = 40-70 ns).In contrast to triplet sensitization, there is no evidence of triplet oxiranes formed via direct excitation.Direct photolysis of the oxiranes appears to result in singlet-mediated photochemistry which initially gives rise to one-bond fragmentation yielding the ultra-short-lived ground-state yieldes.Direct photolysis also leads to the formation of 1-naphthaldehyde and 1-naphthylcarbene via either two-bond fragmentation of the singlet excited oxirane or fragmentation of the ground-state carbonyl ylides.A portion of the fragmentation process appears to occur adiabatically as evidenced by the observation of triplet 1-naphthaldehyde in the transient absorption phenomena.In acetonitrile, the transient absorption spectra from direct laser photolysis (308 nm) reveal evidence for photoionization of the oxiranes giving radical cations (λmax ca. 620 nm).
Application of iron catalyst in reductive coupling reaction and preparation method of aromatic ring and heterocyclic derivative
-
Paragraph 0042-0050, (2020/07/12)
The invention provides an application of an iron catalyst in a reductive coupling reaction of a phenol derivative and an alkyl halide. The iron catalyst is ferrous bromide or ferrous iodide. The invention also provides a preparation method of an aromatic ring and heterocyclic derivative, and the aromatic ring and heterocyclic derivative is prepared by adopting the iron catalyst to catalyze the reductive coupling reaction of a phenol derivative and an alkyl halide. According to the method, the iron catalyst is applied to the reductive coupling reaction of the phenol derivative and the alkyl halide for the first time, the iron catalyst is low in cost and free of toxicity, and the preparation cost is also reduced due to the use of the phenol derivative. The aromatic ring and heterocyclic ringderivative is prepared by taking the phenol derivative and the alkyl halide as reactants, tetramethylethylenediamine as a ligand, lithium methoxide as an alkali and methyl tert-butyl ether as a solvent, the preparation process is simple and easy to control, the cost is relatively low, the yield is relatively high, the problems of high cost, high toxicity, environmental unfriendliness and the likeof a catalyst and reaction raw materials are effectively solved, and the method has a wide application prospect.
Nickel-catalyzed cross-coupling of umpolung carbonyls and alkyl halides
Zhu, Dianhu,Lv, Leiyang,Qiu, Zihang,Li, Chao-Jun
, (2019/05/22)
An effective nickel-catalyzed cross-coupling of Umpolung carbonyls and alkyl halides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
Nickel-Catalyzed Cross-Coupling of Umpolung Carbonyls and Alkyl Halides
Zhu, Dianhu,Lv, Leiyang,Qiu, Zihang,Li, Chao-Jun
, p. 6312 - 6322 (2019/05/24)
An effective nickel-catalyzed cross-coupling of Umpolung carbonyls and alkyl halides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
Ionic iron(III) complexes bearing a dialkylbenzimidazolium cation: Efficient catalysts for magnesium-mediated cross-couplings of aryl phosphates with alkyl bromides
Li, Zhuang,Lu, Bing,Sun, Hongmei,Shen, Qi,Zhang, Yong
, (2017/07/24)
A series of ionic iron(III) complexes of general formula [HLn][FeX4] (HL1?=?1,3-dibenzylbenzimidazolium cation, X?=?Cl, 1; HL1, X?=?Br, 2; HL2?=?1,3-dibutylbenzimidazolium cation, X?=?Br, 3; HL3?=?1,3-bis(diphenylmethyl)benzimidazolium cation, X?=?Br, 4) were easily prepared in high yields by the direct reaction of FeX3 with 1 equiv. of [HLn]X under mild conditions. All of them were characterized using elemental analysis, Raman spectroscopy and electrospray ionization mass spectrometry, and X-ray crystallography for 1 and 4. In the presence of magnesium turnings and LiCl, these air- and moisture-insensitive complexes showed high catalytic activities in direct cross-couplings of aryl phosphates with primary and secondary alkyl bromides with broad substrate scope, wherein complex 4 was the most effective.
Kinetic Isotope Effects as Probes of the Mechanism of Reaction of 1-Naphthylcarbene with Cyclohexane and Toluene
Griffin, G. William,Horn, Keith A.
, p. 4919 - 4926 (2007/10/02)
The rates of reaction of 1-naphthylcarbene (1-NC) in hydrocarbon solution have been measured with excimer laser flash photolysis of 1-naphthyldiazomethane.The kinetic data were obtained by monitoring the growth of the 1-naphthylmethyl radical (1-NCH) at 370 nm.The observed kinetic deuterium isotope effect for the reaction of 1-NC with cyclohexane (cyclohexane-d12) in 2,2,4-trimethylpentane (kH/kD = 1,32 +/- 0.17) and the high CH insertion to H-atom abstraction product ratio are consistent with largely singlet reactivity for 1-NC.In toluene, where addition to the aromatic ring is favored over hydrogen atom abstraction, the measured inverse isotope effect (kH/kD = 0.52 +/- 0.05) also argues for predominantly singlet reactivity and a small singlet-triplet energy gap.The Arrhenius activation parameters measured for the reaction of NC with cyclohexane and toluene were Eact = 2.43 +/- 0.19 kcal/mol, log (A, s-1) = 7.70 +/- 0.15 and Eact = 1.93 +/- 0.38 kcal/mol, log (A, s-1) = 7.28 +/- 0.30, respectively.
1-Naphthylcarbene: Spectroscopy, Kinetics, and Mechanisms
Barcus, R. L.,Hadel, L. M.,Johnston, L. J.,Platz, M. S.,Savino, T. G.,Scaiano, J. C.
, p. 3928 - 3937 (2007/10/02)
The reactions of 1-naphthylcarbene have been examined by using laser flash photolysis techniques.Generation of the carbene from the diazo precursor in hydrocarbon solvents leads to the formation of 1-naphthylmethyl radicals, which were characterized by their absorption at 363 nm.However, product studies in cyclohexane and cyclohexane-d12 reveal that the main reaction path is carbene insertion into the C-H bond rather than H abstraction. 1-Naphthylcarbene reacts readily with nitriles to yield nitrile ylides which can also be generated from the corresponding azirine.For example, the carbene reacts with acetonitrile with a rate constant of 4.6 X 1E5 M-1s-1 at 300 K to yield an ylide that can be trapped readily with electron-deficient olefins, such as diethyl fumarate.Reaction of the carbene with oxygen (k = 3.5 X 1E9 M-1 s-1) yields the carbonyl oxide (λmax 435 nm).Other reactions examined include halogen abstraction, addition to ketones, and reactions with triethylamine, pyridine, and ethers.The absolute kinetics of the various reactions were examined by monitoring the formation of the products (e.g., ylides, radicals, etc.), since the carbene spectrum was not detected directly.
Photochemistry of Naphthylmethyl Halides. Direct and Sensitized Paths to Homolytic and Heterolytic Carbon-Halogen Bond Cleavage
Slocum, Gregory H.,Schuster, Gary B.
, p. 2177 - 2185 (2007/10/02)
Photolysis of the 1-(halomethyl)naphthalenes (X=Cl, Br, I) in methanol and in cyclohexane solution was investigated.Direct and sensitized irradiation leads to carbon-halogen bond cleavage.In methanol solution direct irradiation leads to products of carbon-halogen bond heterolysis, i.e. (methoxymethyl)naphthalene, as well as products derived from bond homolysis.In cyclohexane only homolysis products are observed.The mechanism of the photoreactions was probed by laser spectroscopy, sensitization, and quenching techniques.The results indicate that bond cleavage occurs from excited singlet states but not from the lowest triplet state.Also, an exciplex between sensitizers and the (halomethyl)naphthalene also undergoes carbon-halogen bond cleavage.
