The Experts below are selected from a list of 4968 Experts worldwide ranked by ideXlab platform
Lisa Mcelwee-white - One of the best experts on this subject based on the ideXlab platform.
-
Transition Metal‐Catalyzed Oxidative Carbonylation of Amines to Ureas
European Journal of Organic Chemistry, 2007Co-Authors: Delmy J. Diaz, Ampofo K. Darko, Lisa Mcelwee-whiteAbstract:The synthesis of ureas from amines has traditionally been accomplished with stoichiometric reactions of phosgene or its derivatives, which are associated with environmental and waste disposal issues. Because of the prevalence of urea moieties in molecules of interest for several applications, alternative catalytic routes for the Oxidative conversion of amines to ureas using CO as the carbonyl source have been developed. This microreview discusses recent developments in transition metal-catalyzed Oxidative Carbonylation of amines to ureas as an alternative to phosgene and its derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
-
Selective catalytic Oxidative Carbonylation of amino alcohols to ureas.
The Journal of organic chemistry, 2006Co-Authors: Delmy J. Diaz, Keisha-gay Hylton, Lisa Mcelwee-whiteAbstract:Amino alcohols undergo W(CO)6-catalyzed Oxidative Carbonylation to the corresponding hydroxyalkylureas without protection of the hydroxyl group. Selected examples of 1,2-, 1,3-, 1,4-, and 1,5-amino alcohols were converted to the ureas in good to excellent yields, with only small amounts of the cyclic carbamates being formed. In contrast, the phosgene derivatives CDI and DMDTC undergo stoichiometric reactions with the amino alcohol substrates to afford ureas and cyclic carbamates with variable selectivity.
-
Preparation of biotin derivatives by catalytic Oxidative Carbonylation of diamines
Green Chemistry, 2005Co-Authors: Yue Zhang, Kara Forinash, Courtney R. Phillips, Lisa Mcelwee-whiteAbstract:Biotin methyl ester and related heterocyclic ureas were synthesized by W(CO)6-catalyzed Oxidative Carbonylation of the corresponding diamines. This procedure provides an alternative to the use of phosgene and phosgene derivatives for formation of the urea moiety.
Raghunath V. Chaudhari - One of the best experts on this subject based on the ideXlab platform.
-
Immobilized Palladium Nanoparticles Catalyzed Oxidative Carbonylation of Amines
Industrial & Engineering Chemistry Research, 2010Co-Authors: Mahesh R. Didgikar, Debdut Roy, Sunil P. Gupte, Sunil S. Joshi, Raghunath V. ChaudhariAbstract:Catalytic application of immobilized palladium nanoparticles for synthesis of ureas by Oxidative Carbonylation of amines has been investigated. This is the first report on Oxidative Carbonylation of amines to ureas using immobilized palladium nanoparticles catalyst. The palladium nanoparticles were immobilized on a NaY zeolite support through 3-aminopropyl-trimethoxysilane (APTS) as anchoring agent. The [Pd]-APTS-Y catalyst along with NaI promoter showed high conversion and selectivity to the desired urea products over several amine compounds including an example of an aliphatic amine precursor even at 333 K. The immobilized catalyst was easily separated and recycled several times without any loss of activity. The role of different solvents, iodide promoters, iodide to Pd ratio, concentration of substrates, and temperature on the overall yield of the reaction was also investigated.
-
Oxidative Carbonylation of aniline over Pd-ZSM-5 catalyst
Catalysis Letters, 1994Co-Authors: S. Kanagasabapathy, A. Thangaraj, S. P. Gupte, Raghunath V. ChaudhariAbstract:The Oxidative Carbonylation of aniline over Pd-ZSM-5 is reported. Pd-ZSM-5 catalyst is found to offer significant advantage with respect to CO2 formation. The average activity of Pd-ZSM-5 catalyst was found to be about 80 times higher compared to soluble metal complex catalysts.
-
Oxidative Carbonylation of n-butylamine using transition metal catalysts
Industrial & Engineering Chemistry Research, 1994Co-Authors: Subbareddiar Kanagasabapathy, P. Sunil Gupte, Raghunath V. ChaudhariAbstract:Oxidative Carbonylation of n-butylamine to methyl N-butylcarbamate has been reported. Several homogeneous and heterogeneous transition metal catalysts have been tested for their activity and selectivity. The effect of promoters, solvents, and temperature has been investigated. Temperature plays a vital role in the selectivity of carbamate
Aiwen Lei - One of the best experts on this subject based on the ideXlab platform.
-
From Ketones, Amines, and Carbon Monoxide to 4‑Quinolones: Palladium-Catalyzed Oxidative Carbonylation
Organic letters, 2017Co-Authors: Yuchen Zhou, Yi Zhou, Chien-wei Chiang, Aiwen LeiAbstract:A novel method of palladium-catalyzed Oxidative Carbonylation of ketones, amines, and carbon monoxide for the synthesis of 4-quinolones has been developed. This protocol provides a straightforward route to construct useful 4-quinolone derivatives from inexpensive chemicals.
-
Aerobic Oxidative Carbonylation of Enamides by Merging Palladium with Photoredox Catalysis
The Journal of organic chemistry, 2016Co-Authors: Kun Liu, Minzhu Zou, Aiwen LeiAbstract:Intramolecular Oxidative Carbonylation reaction is an efficient approach for constructing heterocycles. However, stoichiometric amount of hypervalent metal salts is usually required in this transformation. Here we show an aerobic intramolecular Oxidative Carbonylation of enamides by combining palladium and photoredox catalysis. The dual catalytic system enables oxygen directly as oxidant, which provides a mild and environmentally friendly method for the synthesis of 1,3-oxazin-6-ones.
-
Palladium‐Catalyzed Oxidative Carbonylation of N‐Allylamines for the Synthesis of β‐Lactams
Angewandte Chemie (International ed. in English), 2014Co-Authors: Chao Liu, Heng Zhang, Guanghui Zhang, Wangzheng Zhang, Zhengli Duan, Shu-li You, Aiwen LeiAbstract:β-Lactam scaffolds are considered to be ideal building blocks for the synthesis of nitrogen-containing compounds. A new palladium-catalyzed Oxidative Carbonylation of N-allylamines for the synthesis of α-methylene-β-lactams is reported. DFT calculations suggest that the formation of β-lactams via a four-membered-ring transition state is favorable.
Delmy J. Diaz - One of the best experts on this subject based on the ideXlab platform.
-
transition metal catalyzed Oxidative Carbonylation of amines to ureas
European Journal of Organic Chemistry, 2007Co-Authors: Delmy J. Diaz, Ampofo K. Darko, Lisa McelweewhiteAbstract:The synthesis of ureas from amines has traditionally been accomplished with stoichiometric reactions of phosgene or its derivatives, which are associated with environmental and waste disposal issues. Because of the prevalence of urea moieties in molecules of interest for several applications, alternative catalytic routes for the Oxidative conversion of amines to ureas using CO as the carbonyl source have been developed. This microreview discusses recent developments in transition metal-catalyzed Oxidative Carbonylation of amines to ureas as an alternative to phosgene and its derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
-
Transition Metal‐Catalyzed Oxidative Carbonylation of Amines to Ureas
European Journal of Organic Chemistry, 2007Co-Authors: Delmy J. Diaz, Ampofo K. Darko, Lisa Mcelwee-whiteAbstract:The synthesis of ureas from amines has traditionally been accomplished with stoichiometric reactions of phosgene or its derivatives, which are associated with environmental and waste disposal issues. Because of the prevalence of urea moieties in molecules of interest for several applications, alternative catalytic routes for the Oxidative conversion of amines to ureas using CO as the carbonyl source have been developed. This microreview discusses recent developments in transition metal-catalyzed Oxidative Carbonylation of amines to ureas as an alternative to phosgene and its derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
-
Selective catalytic Oxidative Carbonylation of amino alcohols to ureas.
The Journal of organic chemistry, 2006Co-Authors: Delmy J. Diaz, Keisha-gay Hylton, Lisa Mcelwee-whiteAbstract:Amino alcohols undergo W(CO)6-catalyzed Oxidative Carbonylation to the corresponding hydroxyalkylureas without protection of the hydroxyl group. Selected examples of 1,2-, 1,3-, 1,4-, and 1,5-amino alcohols were converted to the ureas in good to excellent yields, with only small amounts of the cyclic carbamates being formed. In contrast, the phosgene derivatives CDI and DMDTC undergo stoichiometric reactions with the amino alcohol substrates to afford ureas and cyclic carbamates with variable selectivity.
Chungu Xia - One of the best experts on this subject based on the ideXlab platform.
-
a novel and efficient nhc cui nhc n heterocyclic carbene catalyst for the Oxidative Carbonylation of amino compounds
Tetrahedron Letters, 2007Co-Authors: Shuzhan Zheng, Jianming Liu, Chungu XiaAbstract:Abstract Oxidative Carbonylation of amino compounds to prepare corresponding 2-oxazolidinones, ureas, and carbamates selectively in the presence of (NHC)Cu I without any additives was firstly achieved in good yields and selectivities.
-
n heterocyclic carbene palladium complexes as efficient catalysts for the Oxidative Carbonylation of amines to ureas
Helvetica Chimica Acta, 2007Co-Authors: Shuzhan Zheng, Xingao Peng, Jianming Liu, Wei Sun, Chungu XiaAbstract:A highly efficient Oxidative Carbonylation reaction of amines to ureas was developed making use of carbene–palladium complexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.
-
N‐Heterocyclic Carbene–Palladium Complexes as Efficient Catalysts for the Oxidative Carbonylation of Amines to Ureas
Helvetica Chimica Acta, 2007Co-Authors: Shuzhan Zheng, Xingao Peng, Jianming Liu, Wei Sun, Chungu XiaAbstract:A highly efficient Oxidative Carbonylation reaction of amines to ureas was developed making use of carbene–palladium complexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.
-
N-Heterocyclic Carbene-Palladium Complex Catalyzed Oxidative Carbonylation of Amines to Ureas
Chinese Journal of Chemistry, 2007Co-Authors: Shuzhan Zheng, Xingao Peng, Jianming Liu, Wei Sun, Chungu XiaAbstract:Palladium carbene shows high efficiency without any promoter on Oxidative Carbonylation of amines to ureas and a new type of palladium carbene complex containing both an aniline and an NHC ligands was found to be the active species for the reaction.
-
A Highly Efficient Sulfur-Catalyzed Oxidative Carbonylation of Primary Amines and β-Amino Alcohols
Synlett, 2006Co-Authors: Xingao Peng, Chungu XiaAbstract:A highly efficient sulfur-catalyzed Oxidative Carbonylation of aliphatic amines and aliphatic β-amino alcohols to ureas and 2-oxazolidinones, respectively, was developed. Sodium nitrite was involved in the reoxidation of hydrogen sulfide to sulfur in the catalytic Oxidative Carbonylation cycle.
