6269-23-4Relevant academic research and scientific papers
Synthesis of unsymmetrical urea from aryl- or pyridyl carboxamides and aminopyridines using PhI(OAc)2via in situformation of aryl- or pyridyl isocyanates
Hunjan, Mandeep Kaur,Laha, Joydev K.,Singh, Neha
, p. 18815 - 18823 (2021/10/26)
A tandem synthesis of unsymmetrical ureas (N-aryl-N′-pyridylurea andN,N′-bipyridylurea) from aryl- or pyridyl carboxamides and aminopyridinesviaHofmann rearrangement has been reported. In particular, benzamides, picolinamide, nicotinamide, and isonicotinamide generate reactive intermediate isocyanates,in situ, in the presence of PhI(OAc)2, which upon further reaction with aminopyridines form urea derivatives. As the formation of pyridylisocyanates from their corresponding carboxamidesviaHofmann rearrangement remained unexplored previously, attempts have been made to trap the isocyanates. While the three pyridylisocyanates were trapped as their corresponding carbamates, 3-pyridylisocyanate was isolated and characterized. Unlike closely related previous methods reported for urea synthesis, the current method avoids direct use of isocyanates or eliminates the use of toxic phosgene for thein situgeneration of isocyanates.
Copper-Catalyzed Coupling of Amines with Carbazates: An Approach to Carbamates
Wang, Song-Ning,Zhang, Guo-Yu,Shoberu, Adedamola,Zou, Jian-Ping
, p. 9067 - 9075 (2021/07/19)
A new approach for the preparation of carbamatesviathe copper-catalyzed cross-coupling reaction of amines with alkoxycarbonyl radicals generated from carbazates is described. This environmentally friendly protocol takes place under mild conditions and is compatible with a wide range of amines, including aromatic/aliphatic and primary/secondary substrates.
Tandem Condensation/Rearrangement Reaction of 2-Aminohetarene N-Oxides for the Synthesis of Hetaryl Carbamates
Bystrov, Dmitry M.,Zhilin, Egor S.,Fershtat, Leonid L.,Romanova, Anna A.,Ananyev, Ivan V.,Makhova, Nina N.
, p. 3157 - 3163 (2018/08/24)
A new approach to hetaryl carbamates through a tandem condensation/rearrangement reaction of 2-aminohetarene N-oxides was developed. The developed reaction is suitable for both five- and six-membered heterocycles and proceeds through the condensation of 2
A Chemoselective N-Arylation Reaction of 2-Aminopyridine Derivatives with Arynes
Cheng, Bin,Wei, Jian,Zu, Bing,Zhao, Jianfei,Wang, Taimin,Duan, Xiaoguang,Wang, Renqi,Li, Yun,Zhai, Hongbin
, p. 9410 - 9417 (2017/09/23)
A chemoselective N-arylation reaction of 2-aminopyridine derivatives with arynes in good to excellent yields has been described. The N-arylation products could be further applied to the facile construction of benzoisoquinuclidines and isoquinuclidines as
Photolysis and thermolysis of pyridyl carbonyl azide monolayers on single-crystal platinum
Adkinson, Dana K.,Magri, David C.,Pitters, Jason L.,Griffiths, Keith,Norton, Peter R.,Workentin, Mark S.
, p. 1020 - 1028 (2013/09/24)
The photochemical and thermal reactivity of a number of acyl azide-substituted pyridine compounds, namely nicotinyl azide, isonicotinyl azide, picolinyl azide and dinicotinyl azide with investigated as saturated monolayers on a single-crystal Pt(111) surface in an ultrahigh vacuum chamber. Multilayers of the substrates exhibited a maximum rate of desorption at 270 K, above which, stable saturated monolayers formed as characterized by reflection-absorption infrared spectroscopy by observation of C=O and N 3 bands at 1700 cm-1, and 2100 and 1300 cm-1 respectively. The monolayers were stable up to 400 K. Photolysis of the monolayer (or heating above 400 K) results in the formation of the respective isocyanate intermediate after loss of nitrogen as evidenced by the appearance of a new infrared band at 2260 cm-1 with concomitant loss of the azide bands. The resulting isocyanate saturated monolayer is stable in absence of nucleophiles, but can be quenched with appropriate nucleophiles. Saturated monolayers of a number of acyl azide-substituted pyridine compounds, namely nicotinyl azide, isonicotinyl azide, picolinyl azide and dinicotinyl azide, were formed on single-crystal Pt(111) surfaces in a UHV chamber. These monolayers were characterized by RAIR and thermal programmed desorption. Photolysis or thermolysis of these saturated monolayers leads to the corresponding isocyanate via a Curtius rearrangement.
Chloroformate free, scalable approach for the synthesis of organic carbamates and their alkylation
Shewalkar, Mukesh P.,Rao, Ramakrishna R.,Reddy, Veerbhadra,Darandale, Sunil N.,Shinde, Devanand B.
, p. 60 - 64 (2013/07/26)
A convenient method for the synthesis of organic carbamates of 2-aminopyridine without using hazardous chloroformate reagent is developed. This alternate approach for the synthesis of organic carbamates and their alkylation to 2-alkylaminopyridines is more practical and economical to be used on large scale. The amazing behavior of 2- aminopyridine helps in forming organic carbamates unlike 3-aminopyridine and 4-aminopyridine.
Palladium-catalyzed carbonylation of amines: Switchable approaches to carbamates and N,N′-disubstituted ureas
Guan, Zheng-Hui,Lei, Hao,Chen, Ming,Ren, Zhi-Hui,Bai, Yinjuan,Wang, Yao-Yu
supporting information; experimental part, p. 489 - 496 (2012/04/04)
Switchable access to carbamates and ureas has been developed by solvent control palladium-catalyzed carbonylation of aromatic amines under an atmosphere of carbon monoxide. A variety of N-phenylcarbamates and N,N′- diphenylureas was easily synthesized in good to excellent yields from readily available aromatic amines under mild conditions. Copyright
Unexpected Reaction of Oximinoacetoacetate with Amines: A Novel Synthesis of Carbamates
Elghamry, Ibrahim
experimental part, p. 3010 - 3015 (2009/12/01)
The synthesis of alkyl carbamates by a solvent-free reaction of oximinoacetoacetate and amine at 130C is reported. A preliminary mechanism to this unexpected reaction is also given.
Indium-catalyzed reaction for the synthesis of carbamates and carbonates: selective protection of amino groups
Kim, Joong-Gon,Jang, Doo Ok
experimental part, p. 2688 - 2692 (2009/08/09)
We developed a simple, efficient, and selective method for preparing organic carbamates and carbonates using a catalytic amount of indium. A wide range of carbamates and carbonates were synthesized in high yields. The method is also applicable to the selective protection of amino groups under mild conditions.
