A robust allylic palladium-NHC complex exhibited extremely high catalytic activity toward aminocarbonylation of various aryl iodides under atmospheric carbon monoxide pressure. A broad range of secondary and primary amines were tolerated. A gram scale synthesis of the anticancer drug tamibarotene further highlightes the practical applicability of the protocol.
W. Fang, Q. Deng, M. Xu, T. Tu, Org. Lett., 2013, 15, 3678-3681.
Pd-catalyzed carbonylation chemistry applying a two-chamber system with crystalline and nontransition metal based sources of carbon monoxide and ammonia is suitable for the synthesis of various primary amides with good functional group tolerance. This approach is also useful for accessing carbon isotope labeled derivatives.
D. U. Nielsen, R. H. Taaning, A. T. Lindhardt, T. M. GÝgsig, T. Skrydstrup, Org. Lett., 2011, 13, 4454-4457.
An efficient generation of a stoichiometric amount of carbon monoxide by Zn-mediated reduction of oxalyl chloride can replace the use of excess toxic gaseous CO in palladium-catalyzed alkoxy-/amino-/hydrogen-/hydroxycarbonylation processes providing esters, amides, aldehydes, and carboxylic acids in very good yields.
M. Markovič, P. Lopatka, P. Koůš, T. Gracza, Org. Lett., 2015, 17, 5618-5621.
A palladium-catalyzed aminocarbonylation of aryl and heteroaryl iodides under phosphine-free conditions enables the synthesis of primary amides in excellent yields using methoxylamine hydrochloride as an ammonia equivalent, that undergoes sequential carbonylation and demethoxylation under mild reaction conditions. The procedure does not require a phosphine ligand and takes place in short reaction times at low temperatures.
S. T. Gadge, B. M. Bhanage, Synlett, 2014, 25, 85-88.
Pd/C catalyzes an oxidative N-dealkylation/carbonylation of tertiary amines to tertiary amides by using molecular oxygen as a sole oxidant without ligands, additives, bases, and cocatalysts. Various tertiary amines as well as aryl iodides provide desired products in very good yield.
R. S. Mane, B. M. Bhanage, J. Org. Chem., 2016, 81, 1223-1228.
Conditions for the rapid hydrolysis of chloroform to carbon monoxide (CO) in the presence of heterogeneous CsOH∑H2O enable palladium-catalyzed aminocarbonylation of aryl, vinyl, and benzyl halides with a broad range of primary and secondary amines in very good yields.
S. N. Gockel, K. L. Hull, Org. Lett., 2015, 17, 3236-3239.
An efficient ligand-free protocol for the amincocarbonylation of aryl iodides with aromatic and aliphatic amines afforded the desired amides in excellent yields using a low loading of palladium(II) acetate as catalyst in water under mild operating conditions. The system tolerated a wide variety of hindered and functionalized substrates.
P. J. Tambade, Y. P. Patil, M. J. Bhanushali, B. M. Bhanage, Synthesis, 2008, 2347-2352.
Phosphonium bromide ionic liquids are superior media in the carbonylation of aryl and vinyl halides. Formation of acid bromide intermediates was detected in control experiments providing an extended view on the overall catalytic cycle involved. Solvent-free product isolation and recycling of the ionic liquid containing active Pd-catalyst are also demonstrated.
J. McNulty, J. J. Nair, A. Robertson, A. Lei, Org. Lett., 2007, 9, 4575-4578.
An efficient and practical molybdenum-mediated carbonylation of aryl and heteroaryl halides with a variety of nucleophiles using microwave irradiation offers a wide scope and proceeds in good to excellent yields.
B. Roberts, D. Liptrot, L. Alcaraz, T. Luker, M. J. Stocks, Org. Lett., 2010, 12, 4280-4283.
In a simple, Mo-mediated carbamoylation reaction of aryl halides, the incorporation of carbon monoxide is so efficient that it requires only a slight excess amount of carbon monoxide in the form of its molybdenum complex, Mo(CO)6. The reaction is applicable for the synthesis of a wide variety of not only secondary and tertiary amides but also primary amides by using aqueous ammonia.
W. Ren, M. Yamane, J. Org. Chem., 2010, 75, 8410-8415.
A Pd-catalyzed aminocarbonylation of aryl bromides into the corresponding Weinreb amides at atmospheric pressure efficiently transforms eletron-deficient, - neutral, and -rich aryl bromides.
J. R. Martinelli, D. M. M. Freckmann, S. L. Buchwald, Org. Lett., 2006, 8, 4795-4797.
Molybdenum hexacarbonyl is a convenient and solid carbon monoxide source in a microwave-accelerated palladium-catalyzed aminocarbonylation of aryl bromides and iodides. 16 different aromatic amides were synthesized under air in good yields after only 15 min of controlled microwave irradiation.
J. Wannberg, M. Larhed, J. Org. Chem., 2003, 68, 5750-5753.
Optimized reaction conditions for a Heck-type carbonylation of (hetero)aryl bromides with [Fe(CO)5] enable alkoxycarbonylations in the presence of methanol and butanol and aminocarbonylations in the presence of various amines, including aniline and benzotriazole, with reasonable results.
M. Babjak, O. CaletkovŠ, D. ĎurišovŠ, T. Gracza, Synlett, 2014, 25, 2579-2584.
The use of Mo(CO)6 and an amine enables a regiospecific, Pd-free aminocarbonylation of various terminal alkynes. The Mo(CO)6-amine system played a dual role as complexing agent and as CO donor.
A. Nagarsenkar, S. K. Prajapti, S. D. Guggilapu, B. N. Babu, Org. Lett., 2015, 17, 4592-4595.
A general Pd-catalyzed double carbonylation of aryl iodides with secondary or primary amines provides α-ketoamides in high yields with excellent chemoselectivities at atmospheric CO pressure. This transformation proceeds successfully even at room temperature and in the absence of any ligand and additive.
H. Du, Q. Ruan, M. Qi, W. Han, J. Org. Chem., 2015, 80, 7816-7823.
A palladium-catalyzed carbonylation of urea derivatives with aryl iodides and bromides afforded N-benzoyl ureas in very good yields using near-stoichiometric amounts of carbon monoxide generated from the decarbonylation of 9-methylfluorene-9-carbonyl chloride as CO precursor. The synthetic protocol displayed good functional group tolerance. The methodology is also highly suitable for 13C isotope labeling.
K. Bjerglund, A. T. Lindhardt, T. Skrydstrup, J. Org. Chem., 2012, 77, 3793-3799.
A one-pot multicomponent carbonylation/amination sequence enables a convenient synthesis of N-acylguanidines. A formation of an N-cyanobenzamide intermediate from the Pd(0)-catalyzed carbonylative coupling of cyanamide and aryl iodides or bromides is followed by amination with various amines to provide the final N-acylguanidines in good yields. Furthermore, various heterocycles were prepared from the N-acylguanidines.
L. Ňkerbladh, L. S. Schembri, M. Larhed, L. R. Odell, J. Org. Chem., 2017, 82, 12520-12529.