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Carbonylation Reaction (carbonylation + reaction)
Selected AbstractsDouble Carbonylation Reactions of Enynols and Thiols to Form Thioester Substituted 6-Membered Ring Lactones.CHEMINFORM, Issue 4 2007Hong Cao Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Pd/C/PPh3: A Simple and Efficient Catalyst System for Double Carbonylation ReactionsCHINESE JOURNAL OF CHEMISTRY, Issue 4 2009Jianming LIU Abstract The double carbonylation of iodobenzene and diethylamine proceeds smoothly in the presence of Pd/C and carbon monoxide to afford the corresponding , -keto amide in good yields with excellent selectivity. In addition, other aryl iodides and secondary amines also react under similar conditions to form , -keto amides in good yields. [source] Synthesis of [11C- carbonyl]hydroxyureas by a rhodium-mediated carbonylation reaction using [11C]carbon monoxideJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5 2006Julien Barletta Abstract [11C]Hydroxyurea has been successfully labelled using [11C]carbon monoxide at low concentration. The decay-corrected radiochemical yield was 38±3%, and the trapping efficiency of [11C]carbon monoxide in the order of 90±5%. This synthesis was performed by a rhodium-mediated carbonylation reaction starting with azidotrimethylsilane and the rhodium complex being made in situ by chloro(1,5-cyclooctadiene)rhodium(I) dimer ([Rh(cod)Cl]2) and 1,2- bis(diphenylphosphino)ethane (dppe). (13C)Hydroxyurea was synthesized using this method and the position of the labelling was confirmed by 13C-NMR. In order to perform accurate LC,MS identification, the derivative 1-hydroxy-3-phenyl[11C]urea was synthesized in a 35±4% decay-corrected radiochemical yield. After 13 µA h bombardment and 21 min synthesis, 1.6 GBq of pure 1-hydroxy-3-phenyl[11C]urea was collected starting from 6.75 GBq of [11C]carbon monoxide and the specific radioactivity of this compound was in the order of 686 GBq/µmol (3.47 nmol total mass). [11C]Hydroxyurea could be used in conjunction with PET to evaluate the uptake of this anticancer agent into tumour tissue in individual patients. Copyright © 2006 John Wiley & Sons, Ltd. [source] Synthesis of [1- 11C]ethyl iodide from [11C]carbon monoxide and its application in alkylation reactionsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 11 2004Jonas Eriksson Abstract A method is presented for preparing [1- 11C]ethyl iodide from [11C]carbon monoxide. The method utilizes methyl iodide and [11C]carbon monoxide in a palladium-mediated carbonylation reaction to form a mixture of [1- 11C]acetic acid and [1- 11C]methyl acetate. The acetates are reduced to [1- 11C]ethanol and subsequently converted to [1- 11C]ethyl iodide. The synthesis time was 20 min and the decay-corrected radiochemical yield of [1- 11C]ethyl iodide was 55 ± 5%. The position of the label was confirmed by 13C-labelling and 13C-NMR analysis. [1- 11C]Ethyl iodide was used in two model reactions, an O -alkylation and an N -alkylation. Starting with approximately 2.5 GBq of [11C]carbon monoxide, the isolated decay-corrected radiochemical yields for the ester and the amine derivatives were 45 ± 0.5% and 25 ± 2%, respectively, based on [11C]carbon monoxide. Starting with 10 GBq of [11C]carbon monoxide, 0.55 GBq of the labelled ester was isolated within 40 min with a specific radioactivity of 36 GBq/µmol. Copyright © 2004 John Wiley & Sons, Ltd. [source] A Microfluidic Approach to the Rapid Screening of Palladium-Catalysed Aminocarbonylation ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Philip Abstract The evaluation and selection of the most appropriate catalyst for a chemical transformation is an important process in many areas of synthetic chemistry. Conventional catalyst screening involving batch reactor systems can be both time-consuming and expensive, resulting in a large number of individual chemical reactions. Continuous flow microfluidic reactors are increasingly viewed as a powerful alternative format for reacting and processing larger numbers of small-scale reactions in a rapid, more controlled and safer fashion. In this study we demonstrate the use of a planar glass microfluidic reactor for performing the three-component palladium-catalysed aminocarbonylation reaction of iodobenzene, benzylamine and carbon monoxide to form N -benzylbenzamide, and screen a series of palladium catalysts over a range of temperatures. N -Benzylbenzamide product yields for this reaction were found to be highly dependent on the nature of the catalyst and reaction temperature. The majority of catalysts gave good to high yields under typical flow conditions at high temperatures (150,°C), however the palladium(II) chloride-Xantphos complex [PdCl2(Xantphos)] proved to be far superior as a catalyst at lower temperatures (75,120,°C). The utilised method was found to be an efficent and reliable way for screening a large number of palladium-catalysed carbonylation reactions and may prove useful in screening other gas/liquid phase reactions. [source] Palladium(II)-catalyzed catalytic aminocarbonylation and alkoxycarbonylation of terminal alkynes: regioselectivity controlled by the nucleophilesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2010Rami Suleiman Abstract The aminocarbonylation and alkoxycarbonylation reactions of terminal alkynes took place smoothly and efficiently using a catalyst system Pd(OAc)2,dppb,p -TsOHCH3CNCO under relatively mild experimental conditions. The catalytic system was tested and optimized using two different nucleophiles: alcohols and amines. Phenylacetylene (1a) was considered as an alkyne along with diisobutylamine (2b1) and methanol (2c1) as nucleophiles. The results showed significant differences in the conversion of 1a and in the selectivity towards the gem or trans unsaturated esters or amides with these nucleophiles. The effects of the type of palladium catalysts, the type of ligands, the amount of dppb and the solvents were carefully studied. With diisobutylamine (2b1), excellent regioselectivity towards the 2-acrylamides (gem isomer, 3ab1) was almost always observed, while trans -,,,-unsaturated esters 4ac1 was the predominant product with methanol (2c1) as a nucleophile. This remarkable sensitivity in the selectivity of the reaction indicates two different possible mechanistic pathways for these carbonylation reactions. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||