37389-92-7

Upstream product

• 868-84-8 S,S-dimethyl dithiocarbonate 
• 104-84-7 para-methylbenzylamine 
• 201230-82-2 carbon monoxide 
• 67-56-1 methanol 
• 106-49-0 p-toluidine 
• 57-13-6 urea 
• 68-12-2 N,N-dimethyl-formamide 
• 108-88-3 toluene 
• 35675-44-6 4-methylphenylacetyl chloride 
• 124-38-9 carbon dioxide 
• 56651-57-1 4-tolylmethyl isocyanate 
• 123558-63-4 2,2,2-Trichloro-N-(4-methyl-benzyl)-acetamide 
• 594-65-0 trichloroacetamide 
• 104-82-5 4-Methylbenzyl chloride 

Downstream Products

• 67-56-1 methanol 
• 104-84-7 para-methylbenzylamine 

Relevant academic research and scientific papers

Amine-Responsive Disassembly of AuI–CuI Double Salts for Oxidative Carbonylation

A sensitive amine-responsive disassembly of self-assembled AuI-CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2][CuI2] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2]+ and the capacity of [CuI2]? on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.

Method for preparing symmetric urea compound

The invention provides a novel reaction system for synthesizing a symmetric urea compound by taking CO2 as a carbonylation reagent, wherein Lewis base and hydrosilane are used as accelerators and efficiently enable an aromatic/aliphatic primary amine compound to react with normal-pressure CO2 to generate corresponding symmetric urea compounds containing different functional groups under mild conditions (100 DEG C, diglyme). According to the method, normal-pressure CO2 is used as an environmentally-friendly non-toxic carbonylation reagent, and cheap Lewis base and PMHS (industrial silicon waste) are used as accelerators, so that the use of toxic carbonylation reagents, isocyanate, high-pressure CO2, expensive dehydrating agents and precious metals is avoided, purification and separation ofintermediates are not needed, pure products can be obtained only through simple suction filtration and separation after the reaction is finished, and the method is an efficient and novel synthesis method and has high industrial application value.

Iron-catalyzed urea synthesis: Dehydrogenative coupling of methanol and amines

Substituted ureas have numerous applications but their synthesis typically requires the use of highly toxic starting materials. Herein we describe the first base-metal catalyst for the selective synthesis of symmetric ureas via the dehydrogenative coupling of methanol with primary amines. Using a pincer supported iron catalyst, a range of ureas was generated with isolated yields of up to 80% (corresponding to a catalytic turnover of up to 160) and with H2 as the sole byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanistic insights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric ureas from amides and amines.

Co-N-doped carbon nanotubes supported on diatomite for highly efficient catalysis oxidative carbonylation of amines with CO and air

Cobalt-nitrogen-doped carbon nanotubes stably supported on diatomite were obtained by employing Co(OAc)2/phenanthroline. The resulting material was found to be excellent catalysts for the carbonylation of a variety of amines with CO other than phosgene. Both high activity and selectivity were achieved in this carbonylation process, and it allows air as a cheap oxidizing agent. Moreover the catalyst could be recycled for several times with relatively higher activity compared to homogeneous catalyst palladium acetate.

Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines

Activation of the N-H bond of amines by a ruthenium pincer complex operating via amine-amide metal-ligand cooperation is demonstrated. Catalytic formyl C-H activation of N,N-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids the direct use of fatal CO. The catalytic carbonylation occurred at low temperature to provide the formamide; a formamide intermediate was isolated. The consecutive addition of different amines provided unsymmetrical urea compounds. The reactions are proposed to proceed via N-H activation of amines followed by CO insertion from DMF and with liberation of dihydrogen.

Ruthenium-Catalyzed Urea Synthesis Using Methanol as the C1 Source

An unprecedented protocol for urea synthesis directly from methanol and amine was accomplished. The reaction is highly atom-economical, producing hydrogen as the sole byproduct. Commercially available ruthenium pincer complexes were used as catalysts. In addition, no additive, such as a base, oxidant, or hydrogen acceptor, was required. Furthermore, unsymmetrical urea derivatives were successfully obtained via a one-pot, two-step reaction.

Transamidation of primary carboxamides, phthalimide, urea and thiourea with amines using Fe(OH)3@Fe3O4 magnetic nanoparticles as an efficient recyclable catalyst

The highly efficient transamidation of primary amides, phthalimide, urea and thiourea with amines catalyzed by magnetic Fe(OH)3@Fe3O4 nanoparticles is described. This magnetic nanocomposite is able to catalyze transamidation reactions of a wide range of the above-mentioned substrates with amines, generating a new amide bond in moderate to good yields. The catalyst exhibited very good recyclability and reusability up to five runs without significant loss of its catalytic activity.

NaIO4-oxidized carbonylation of amines to ureas

Oxidative carbonylation of amines using NaIO4 as the oxidant and NaI as a promoter affords good to excellent yields of ureas from primary amines in the absence of transition metal catalysts. The Royal Society of Chemistry 2009.

Preparation of mono-, di-, and trisubstituted ureas by carbonylation of aliphatic amines with S,S-dimethyl dithiocarbonate

General procedures are reported to prepare N-alkylureas, N,N′-dialkylureas (both symmetrical and unsymmetrical), and N,N,N′-trialkylureas by carbonylation of aliphatic amines, employing S,S-dimethyl dithiocarbonate (DMDTC) as a phosgene substitute. All reactions were carried out in water. Symmetrical disubstituted ureas were prepared directly working at 60°C with a molar ratio of DMDTC:amine = 1:2, preferably under nitrogen. Unsymmetrical ureas were prepared in two steps via S-methyl N-alkyl-thiocarbamate intermediates, which are formed selectively in the first step at room temperature. These intermediates react in the second step with ammonia or various aliphatic amines, both primary and secondary, at temperatures varying between 50 and 70°C. All the target ureas were obtained in high yields (28 examples, average yield 94%) and with very high purity (generally >99.2%). Also to be noted is the recovery of a co-product of industrial interest, methanethiol, in an amount of two moles for each mole of DMDTC, with complete exploitation of the reagent. Georg Thieme Verlag Stuttgart.

NEW PROCEDURES FOR THE SYNTHESIS OF SYMMETRICAL BISBENZYLATED UREAS BASED ON N-BENZYLTRICHLOROACETAMIDES

Treatment of N-benzylated trichloroacetamides 4, obtained by three different procedures, with potassium carbonate in dimethylsulfoxide affords simmetrical bisbenzylated ureas 5.