17217-84-4Relevant articles and documents
Kobayashi et al.
, p. 905 (1970)
Experimental and Theoretical Studies on Gas-Phase Fragmentation Reactions of Protonated Methyl Benzoate: Concomitant Neutral Eliminations of Benzene, Carbon Dioxide, and Methanol
Xia, Hanxue,Zhang, Yong,Attygalle, Athula B.
, p. 1601 - 1610 (2018)
Protonated methyl benzoate, upon activation, fragments by three distinct pathways. The m/z 137 ion for the protonated species generated by helium-plasma ionization (HePI) was mass-selected and subjected to collisional activation. In one fragmentation path
Phosphorus-Based Organocatalysis for the Dehydrative Cyclization of N-(2-Hydroxyethyl)amides into 2-Oxazolines
Soleymani Movahed, Farzaneh,Foo, Siong Wan,Mori, Shogo,Ogawa, Saeko,Saito, Susumu
supporting information, p. 243 - 257 (2021/12/17)
A metal-free, biomimetic catalytic protocol for the cyclization of N-(2-hydroxyethyl)amides to the corresponding 2-oxazolines (4,5-dihydrooxazoles), promoted by the 1,3,5,2,4,6-triazatriphosphorine (TAP)-derived organocatalyst tris(o-phenylenedioxy)cyclotriphosphazene (TAP-1) has been developed. This approach requires less precatalyst compared to the reported relevant systems, with respect to the phosphorus atom (the maximum turnover number (TON) ～30), and exhibits a broader substrate scope and higher functional-group tolerance, providing the functionalized 2-oxazolines with retention of the configuration at the C(4) stereogenic center of the 2-oxazolines. Widely accessible β-amino alcohols can be used in this approach, and the cyclization of N-(2-hydroxyethyl)amides provides the desired 2-oxazolines in up to 99% yield. The mechanism of the reaction was studied by monitoring the reaction using spectral and analytical methods, whereby an 18O-labeling experiment furnished valuable insights. The initial step involves a stoichiometric reaction between the substrate and TAP-1, which leads to the in situ generation of the catalyst, a catechol cyclic phosphate, as well as to a pyrocatechol phosphate and two possible active intermediates. The dehydrative cyclization was also successfully conducted on the gram scale.
Selective C-C bond cleavage of amides fused to 8-aminoquinoline controlled by a catalyst and an oxidant
Li, Sen,Jie, Kun,Yan, Wenjie,Pan, Qingjun,Zhang, Min,Wang, Yufeng,Fu, Zhengjiang,Guo, Shengmei,Cai, Hu
supporting information, p. 13820 - 13823 (2020/11/18)
Herein, copper-catalyzed direct C-C bond cleavage of amides fused to 8-aminoquinoline as a directing group to form urea in the presence of amines and dioxygen is reported. Compared to the previous C-H aminations of amides via C-H activation, this reaction presents a catalyst and oxidant controlled C-C bond cleavage strategy that enables amidation through a radical process. CuBr/Ag2CO3/O2 shows the best catalytic result at 150 °C. A series of aryl and alkyl amides were compatible with this transformation. Notably, this method provided access to cyclohexanone, one of the most important industrial materials. The pathway of this reaction was investigated.
Copper-catalyzed oxidative cleavage of Passerini and Ugi adducts in basic medium yielding α-ketoamides
Ghoshal, Anirban,Ambule, Mayur D.,Sravanthi, Revoju,Taneja, Mohit,Srivastava, Ajay Kumar
supporting information, p. 14459 - 14474 (2019/10/01)
The aerobic oxidative cleavage of Passerini and Ugi adducts in the presence of base and copper(i) iodide is studied in detail. The oxidative cleavage yields α-ketoamides along with acids and amides from Passerini and Ugi adducts respectively. Mechanistic investigations revealed that the reaction proceeds via a radical pathway involving molecular oxygen. Control experiments with 18O-labeled Passerini adducts confirmed that molecular oxygen is the source of oxygen in α-ketoamides. A variety of Passerini and Ugi adducts were studied to explore the effect of substitution. Overall, the present study provides an insight into the reactivity of Passerini and Ugi adducts in strong basic conditions along with a method to prepare α-ketoamides.
