Xi:Irritant;
106-30-9Relevant articles and documents
The Pd3(dppm)3 (CO)2+ cluster: An efficient electrochemically assisted Lewis acid catalyst for the fluorination and alcoholysis of acyl chlorides
Lemaitre, Frederic,Lucas, Dominique,Mugnier, Yves,Harvey, Pierre D.
, p. 7537 - 7540 (2002)
The dicationic palladium cluster Pd3(dppm)3-(CO)2+ (dppm = bis(diphenylphosphino)methane) reacts with acid chlorides RCOCl (R = n-C6H13, t-Bu, Ph) to afford quantitatively the chloride adduct Pd3(dppm)3(CO)(Cl)+ and the acyl cation RCO+ as the organic counterpart. The dicationic reactive cluster can be reformed by electrolyzing the chloride complex with a copper anode leaving CuCl as a byproduct. The combination of these two reactions provides an electrocatalytic way to form the acylium from the acid chloride. Indeed, in CH2Cl2, 0.2 M NBu4PF6, or NBu4BF4, the electrolysis of the acid chloride in the presence of a catalytic amount of the cluster (1%) gives in good yields the acid fluoride RCOF, arising from the coupling of the acylium with a F- issued from the fluorinated supporting electrolyte. Alternatively, in CH2Cl2 or 0.2 M NBu4ClO4, by operating with an alcohol R′OH as the nucleophile, the electrolysis gives the ester RC(O)OR′ as the only final product.
Immobilization of palladium acetate on ionic liquid copolymerized polystyrene: A way to eliminate inhibiting effect of imidazolium chloride and enhance catalytic performance
Sugimura, Rie,Kun, Qiao,Tomida, Daisuke,Kume, Yohei,Yokoyama, Chiaki
, p. 874 - 875 (2007)
Immobilization of palladium acetate on a novel polymeric support that is prepared by copolymerization of 3-butyl-1-vinylimidazolium chloride with styrene is demonstrated to be an effective way to eliminate inhibiting effect of imidazolium chloride and enhance catalytic performance. Copyright
Hydroethoxycarbonylation of α-olefins at low pressure of carbon(II) oxide in the presence of the PdCl2(PPh3)2–PPh3–AlCl3 system
Suerbaev, Kh. A.,Kudaibergenov, N. Zh.,Vavasori
, p. 707 - 712 (2017)
High catalytic activity of the PdCl2(PPh3)2–PPh3–AlCl3 system containing AlCl3 as promotor has been demonstrated in the reaction of hydroethoxycarbonylation of hexene-1 and octene-1 at low pressure of carbon(II) oxide (≤25 atm). The reaction yields linear and branched products. The optimal conditions of the process have been elaborated. The target products yield is 84.6–93.8%.
Sulphonic Acid-induced Fragmentation of Dialkyl Acylphosphonates, Formation of Alkyl Carboxylates and Alkyl Sulphonates
Breuer, Eli,Karaman, Rafik,Goldblum, Amiram,Leader, Haim
, p. 2029 - 2034 (1988)
Heating of dialkyl acylphosphonates with sulphonic acids under anhydrous conditions leads to the formation of alkyl sulphonates and alkyl carboxylates. 31P N.m.r. spectroscopy revealed that the reaction of equimolar amounts of dimethyl benzoylphosphonate (1) and toluene-p-sulphonic acid at room temperature gives dimethyl phosphonate (6) in 50percent yield.It is proposed that the by-product of this reaction, benzoic toluene-p-sulphonic anhydride (8), reacts with the excess of toluene-p-sulphonic acid, to yield toluene-p-sulphonic anhydride (9) and benzoic acid.Heating of these two compounds with dimethyl phosphonate was shown to yield methyl toluene-p-sulphonate and methyl benzoate, respectively.A postulated by-product of these reactions is phosphenous acid (HPO2).Quantum mechanical calculations by the MNDO/H method carried out on dimethyl benzoylphosphonate and its protonation products show that the preferred site of protonation of dimethyl benzoylphosphonate is the P=O oxygen, and that protonation at this site is followed by C-P bond breaking, with zero energy of activation, leading to dimethyl phosphite and benzoylium cation.
Oxidation of Diols and Ethers by NaBrO3/NaHSO3 Reagent
Sakaguchi, Satoshi,Kikuchi, Daisuke,Ishii, Yasutaka
, p. 2561 - 2566 (1997)
NaBrO3 combined with NaHSO3 was found to be an excellent oxidizing reagent of alcohols, diols, and ethers under mild conditions. A variety of aliphatic and cyclic diols were selectively oxidized with satisfactory yields to the corresponding hydroxy ketones and/or diketones, which are difficult to selectively prepare due to a concomitant formation of cleaved products. For example, 2-hydroxycyclohexanone and 1,2-cyclohexanedione were selectively formed by allowing 1,2-cyclohexanediol to react with NaBrO3/NaHSO3 reagent in a selected solvent. On the other hand, an alkyl ether, such as dioctyl ether, reacted with NaBrO3/NaHSO3, in water at room temperature to give octyl octanoate in 82% yield. The same oxidation at higher temperature (60°C) produced the α-brominated ester, octyl 2-bromooctanoate, which is considered to be formed through an alkenyl alkyl ether as the intermediate. The treatment of 1-ethoxy-l-heptene with NaBrO3/NaHSO3 afforded ethyl 2-bromoheptanoate and 2-bromoheptanoic acid as the major products.
Hydroalkoxycarbonylation of olefins in the presence of palladium phosphine complexes: High activity and regioselectivity
Chepaikin,Bezruchenko,Suerbaev,Shalmagambetov
, p. 117 - 121 (2006)
Several types of catalyst systems were examined in the olefin hydroalkoxycarbonylation reaction. The systems contained Pd(PPh 3)4, PdCl2(PPh3)2, or some other palladium compounds as a principal component. The second component (promoter) was p-toluenesulfonic acid or diphenyl(m-sulfophenyl)phosphine, which combines both the ligand and promoter functions. An important feature of these systems is their high activity in the hydroalkoxycarbonylation of ethylene and a high regioselectivity (83-100%) in the hydroalkoxycarbonylation of α-olefins with respect to linear products. Thus, it was unnecessary to introduce additional stabilizing ligands to augment the catalyst and promoter. The esters obtained can find application in the pharmaceutical industry and perfumery, as well as in other industries. Nauka/Interperiodica 2006.
Palladium complexes with N-heterocyclic carbene ligands as catalysts for the alkoxycarbonylation of olefins
Roberts, Gina M.,Pierce, Philip J.,Woo, L. Keith
, p. 2033 - 2036 (2013)
Palladium catalysts, generated from Pd(OAc)2 and 2 equiv of N,N-dialkylbenzimidazolium iodide, are effective for the alkoxycarbonylation of olefins in high yields (>90%). Alkoxycarbonylation of 1-hexene in dimethylacetamide is achieved within 24 h at 110 C using 1 mol % catalyst, 1000 psi CO, and ethanol. Reactions can be prepared in air, without the need of an acid additive to produce ethyl 2-methylhexanoate and ethyl heptanoate in approximately a 2:1 ratio.
Cloning and expression of a Baeyer-Villiger monooxygenase oxidizing linear aliphatic ketones from Dietzia sp. D5
Bisagni, Serena,Smus?, Justyna,Chávez, Georgina,Hatti-Kaul, Rajni,Mamo, Gashaw
, p. 161 - 169 (2014)
A Baeyer-Villiger monooxygenase has been identified in the genome sequence of Dietzia sp. D5. Sequence similarity search revealed that the enzyme belongs to a group of BVMOs that are closely related to ethionamide monooxygenase from Mycobacterium tuberculosis (EthA). The BVMO was expressed in E. coli BL21-CodonPlus(DE3)-RP and the best expression was achieved when the E. coli cells were cultivated in terrific broth (TB) at 15 °C and induced with 0.1 mM of IPTG. Since the purified enzyme did not show any measurable activity, the substrate scope of the BVMO has been determined using whole-cell and crude cell extract systems. The enzyme was most active towards linear aliphatic substrates. However, it has shown a moderate degree of conversion for cyclobutanone, 2-methylcyclohexanone, bicyclo[3.2.0]hept-2-en-6-one, phenylacetone and thioanisole. There was no detectable conversion of ethionamide, cyclohexanone and acetophenone.
Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
Bai, Hangyu,Jiang, Weiqi,Li, Qi,Li, Tian,Ma, Shichuang,Shi, Baojun,Wu, Wenjun
, p. 11572 - 11581 (2021/10/12)
A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC50 values of 27.6 and 30.4 μg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 μg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 μg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
Gold Complexes with ADAP Ligands: Effect of Bulkiness in Catalytic Carbene Transfer Reactions (ADAP = Alkoxydiaminophosphine)
Fructos, Manuel R.,Molina, Francisco,Pérez, Pedro J.,Pizarro, Juan Diego
supporting information, (2020/07/14)
A family of gold(I) complexes of composition AuCl(ADAP) (ADAP = alkoxydiaminophosphine) has been synthetized through a one-pot simple protocol in which the ADAP ligand is prepared in situ before reaction with the Au(I) source. Structural data demonstrate that these ADAP ligands exert a trans effect superior to those of phosphine or phosphite ligands. Evaluation of the buried volume (percentVBur) indicates a steric hindrance higher than those of several NHC, PR3, and P(OR3) ligands, in the context of AuCl(L) complexes. These complexes promote the catalytic transfer of a carbene group from ethyl diazoacetate to alkenes and alkanes. In the case of styrene, both the Csp2-H bonds and the Ca? C bond are functionalized, the relative ratio depending on the catalyst employed and correlating well with the percentVBur value. Data available allow proposing that these compounds display quite similar electronic properties but differ in steric properties, a variable that can be readily controlled upon modifying the alkoxy group at the ADAP ligand by simply replacing the starting alcohol employed in the synthesis.
