22164-12-1Relevant articles and documents
Parallel Synthesis of 1H-Pyrazolo[3,4-d]pyrimidines via Condensation of N-Pyrazolylamides and Nitriles
Shah, Akshay A.,Chenard, Lois K.,Tucker, Joseph W.,Helal, Christopher J.
, p. 675 - 680 (2017)
A novel parallel medicinal chemistry (PMC)-enabled synthesis of 1H-pyrazolo[3,4-d]pyrimidines employing condensation of easily accessible N-pyrazolylamides and nitriles has been developed. The presented studies describe singleton and library enablements that allowed rapid generation of molecular diversity to examine C4 and C6 vectors. This chemistry enabled access to challenging alkyl substituents, expanding the overall chemical space beyond that available via typical C(sp2)-C(sp2) coupling and SNAr transformations. Furthermore, monomer group interconversions allowing the use of larger and more diverse amides and carboxylic acids as precursors to nitriles are discussed.
Tropylium-promoted Ritter reactions
Doan, Son H.,Hussein, Mohanad A.,Nguyen, Thanh Vinh
supporting information, p. 8901 - 8904 (2021/09/10)
The Ritter reaction used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuableN-alkyl amide products. However, this reaction has not been frequently used in modern organic synthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the tropylium ion to promote the Ritter reaction. This method works well on a range of alcohol and nitrile substrates, giving the corresponding products in good to excellent yields. This reaction protocol is amenable to microwave and continuous flow reactors, offering an attractive opportunity for further applications in organic synthesis.
An Unconventional Reaction of 2,2-Diazido Acylacetates with Amines
H?ring, Andreas P.,Biallas, Phillip,Kirsch, Stefan F.
supporting information, p. 1526 - 1539 (2017/04/01)
We have discovered that 2,2-diazido acylacetates, a class of compounds with essentially unknown reactivity, can be coupled to amines through a new strategy that does not involve any reagents. 2,2-Diazido acetate is the unconventional leaving group under carbon–carbon bond cleavage. This reaction leads to the construction of amide bonds, tolerates various functionalities and is performed equally well in numerous solvents under experimentally simple conditions. We also demonstrate that the isolation of the 2,2-diazido acylacetate compounds can be circumvented: Acylacetates were easily fragmented when treated with (Bu4N)N3 and iodine in the presence of an amine at room temperature. By using this method, a broad range of acylacetates with various structural motifs were directly transformed into amides.
