Carbonylation of amines

The most promising approaches for the preparation of technologically important ureas and carbamates by nonphosgene routes are the catalytic oxidative carbonylation of amines in the presence of an alcohol or the reductive carbonylation of nitro 

The oxidative carbonylation of anilines can be performed in milder reaction conditions by using selenium compounds [73]. The most critical disadvantage of 

Alternative sources for carbonyl groups were also investigated. Dimethyl carbonate, for example, efficiently replaces the dangerous CO/O2 mixture in the carbonylation of aliphatic amines to yield alkylcarbamates using ILs as reaction media and catalyst [80]. The solid carbamate can be recovered by simple filtration from the biphasic mixture of dimethyl carbonate/IL after reaction. The IL phase can be 

Ionic liquids have also been found to be efficient reaction media for the activation of CO2 [82-84]. Diurea derivatives are easily obtained from amines and carbon dioxide with a CsOH/ionic liquid catalyst system [83]. N-Substituted 4-methylene-2-oxazolidinones are also efficiently synthesized in IL media by reaction of carbon dioxide with propargylic alcohol and different amines [82]. Other examples include the cycloaddition of CO2 to epoxides to produce cyclic carbonates [85] and synthesis of cyclic urethanes [86,87]. 

Carbonylation ofC C and C = C bonds (Hydroesterification and Aminocarbonylation, Pauson-Khand, and Copolymerization) 

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The alkylurea 576 and oxamide 577 are formed by oxidative carbonylation of amines under CO pressure using Pd/C as a catalyst[518]. The urea formation proceeds under atmospheric pressure using PdCh and CuCl2[519]. The mono-and double carbonylations of / -aminoethanol (578 and 579) afford the cyclic carbamate (oxazolidinones) 580 and oxamide (morpholinediones) 581 [520,521]. 

Carbamates are produced by the oxidative carbonylation of amines in alcohol, and active research on the commercial production of carbamates as a precursor of isoyanates based on this reaction has been carried out. As an example, ethyl phenylcarbamate (582) is produced in a high yield (95%) with... 

Didgikar MR, Roy D, Gupta SP, Joshi SS, Chaudhari RV (2010) Immobilized palladium nanoparticles catalyzed oxidative carbonylation of amines. Ind Eng Chem Res 49 1027-1032... 

Cross double carbonylation of amines and alcohols Oxamates can be prepared by double carbonylation of amines and alcohols in the presence of (CH,CN)2PdCl2 as catalyst with 02 and Cul as oxidant and co-catalyst. This reaction is particularly efficient when applied to (3-amino alcohols. 

The oxidative carbonylation of amines to give ureas is at present one of the most attractive ways for synthesizing this very important class of carbonyl compounds via a phosgene-free approach. Ureas find extensive application as agrochemicals, dyes, antioxidants, resin precursors, synthetic intermediates (also for the production of carbamates and isocyanates), and HIV-inhibitors. Many transition metals (incuding Au [244], Co [248,253-255], Cu [242], Mn [249,256-258], Ni [259], Rh [246,247,260-262], Ru [224,260,263] and especially Pd [219,225,226,264-276], and, more recently, W [277-283]) as well as main-group elements (such as sulfur [284-286] and selenium [287— 292]) have been reported to promote the oxidative carbonylation of amines, usually under catalytic conditions. In some cases, carbamates and/or oxamides are formed as byproducts, thus lowering the selectivity of the process. 

Copper salts, cupric or cuprous also will catalyze the carbonylation of amines. Piperidine, for example, gives a urea derivative with carbon monoxide, and it, too, is probably a metal amide—carbon monoxide insertion reaction. 

The insertion of carbon monoxide was also the key step in the formation of urea derivatives through the oxidative carbonylation of amines. 6-Amino-... 

Insertion by nitrenes 2-55 Carbonylation of amines or nitro or nitroso compounds... 

Exchange of ureas 2-55 Carbonylation of amines 6-17 Addition of amines to isocyanates or isothiocyanates... 

A few of these imply the carbonylation of nitroaromahc substrates [41], or the oxidative carbonylation of amines [42], or the reaction of amines with carbonic acid diesters [11] that are currently available, even on an industrial scale, through phosgene-free routes [43]. 

Scheme 6.31 Carbonylation of amines with C02 in the presence of the catalytic system Ph3SbO/P4S10.

Carbonylation of amines. The carbonylation of amines catalyzed by selenium to give ureas has been known for some time (4,422). Tellurium can also be used as a catalyst, and in this case oxygen is not required to regenerate the catalyst (equation... 

Gabriele B, Salerno G, Mancuso R et al (2004) Efficient synthesis of ureas by direct palladium-catalyzed oxidative carbonylation of amines. J Org Chem 69(14) 4741 1750... 

The disproportionation of manganese carbonyl with nitrogen ligands is reviewed by Hieber et al. (122). Calderazzo has investigated the catalytic carbonylation of amines by manganese carbonyl (30). The corresponding chemistry of rhenium carbonyl remains to be investigated. 

Byerley JJ, Rempel GL, Takebe N, James BR (1971) Catalytic carbonylation of amines using ruthenium complexes under mild conditions. J Chem Soc D Chem Commun 1482-1483... 

The oxidative carbonylation of amines to formamides was also reported in 2001 in up to 94% yield using Ph3PAuTCl as catalyst and oxygen as oxidant in methanol 7... 

F. Calderazzo, The Manganese-Catalyzed Carbonylation of Amines, Inorg. Chem. 4, 293-296 (1965). 

Imidazolium alkylselenite ionic liquids were found to be efficient catalysts/solvents for the oxidative carbonylation of amines,1371 but in general the synthesis of carbonyl compounds is carried out in the presence of a palladium catalyst. The first example of such a transformation stems from... 

Examples of gold-catalyzed carbonylation of amines and olefins exist related to the activation of carbonyl. The first case involves the formation of carbamates from anilines and CO in the presence of alcohols or the production of acetamides from aliphatic amines. In these examples, Au(I) (usually [AuCl(PPh3)]) catalysts are preferred. For the carbonylation of olefins, gold(I) carbonyls are prepared in situ in sulfiu ic acid media to afford carboxyhc acids. ... 

The oxidative carbonylation of amines has been performed using palladium complex catalysts. Rhodium and ruthenium complexes have also been sho vn to have catalytic activity in the preparation of carbamates and ureas [93, 94]. An example is sho vn in Eq. 11.47. The usual carbonylation of amines to give formamides vas discussed in Section 11.2.3. 

Ureas and formamides. Carbonylation of amines takes place to afford ureas on... 

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