Amides are a class of very important organic compounds and are widely used in medicine, pesticides, materials and chemical related fields. For example, Propanil is a highly selective contact herbicide of amides and is a specific drug for controlling valerian; Bucinnazine is a rapid-acting analgesic drug used clinically to treat migraine and trigeminal neuralgia. , inflammatory and traumatic pain, etc. Valsartan is a highly effective drug for the treatment of hypertension. Therefore, the efficient synthesis of amide compounds has always been one of the most important research areas in organic chemistry, and plays an important role in the development of life sciences and human health.
The transition metal catalyzed olefin hydrinoamine carbonylation is one of the most important methods for the synthesis of amides, with an atomic economy of 100%, but in contrast to hydroformylation, the carbonylation of olefinic hydrogen amines catalyzed by transition metals The reason for the lack of research is that the effective catalytic reaction of this type of reaction should be initiated by [MH]. Since [MH] can only be produced under relatively acidic conditions, the strong basicity of aliphatic amines (pkb<5) inhibits the generation of [MH], and the reported olefin hydrogen amine carbonylation reaction is only applicable to aromatic amines. . Therefore, how to overcome the "basis" of the reaction caused by the strong alkalinity of fatty amines is a key scientific problem that must be solved.
Based on this issue, the research team led by Huang Hanmin, a researcher at the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, based on the previous CN bond activation study (Angew. Chem. Int. Ed. 2014, 53, 7272; J. Am. Chem. Soc 2013, 135, 18327; J. Am. Chem. Soc. 2012, 134, 20613), using the weak alkalinity of amine acetals and the activation of CN bonds through the use of aliphatic amine acetals as the nitrogen source. Palladium-catalyzed carbonylation of olefins with amine acetals and water is a highly regioselective production of a series of fatty amides at 10 atm of CO.
On this basis, a small co-catalyst system composed of Pd/paraformaldehyde/acid organic small molecule and transition metal was designed, and the carbonylation reaction of alkenyl hydrogenamine involved in various amines was realized, and the chain amide was obtained with high regioselectivity. The catalytic system has solved the scientific problems that have long puzzled the carbonylation of olefinic hydrogen amines and is expected to promote the development of related fields. The study was published in Angew. Chem. Int. Ed. 2015, 54, DOI: 10.1002/anie.201502405, titled Palladium-Catalyzed Hydroaminocarbonylation of Alkenes with Amines: A Strategy to Overcome Basicity-Barrier Imparted by Aliphatic Amines. This method can be used to efficiently synthesize the herbicide diuretics and the quick-acting analgesic drug buclazin in one pot using ethylene or propylene, a cheap and widely available industrial product, as a raw material. The relevant patents are being applied.
The above work has received long-term support from the National Natural Science Foundation of China and the Lanzhou Institute of Chemical Industry's "One-Three-Five" Plan for Key Fostering Projects.
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