19506-88-8Relevant academic research and scientific papers
Dehydration of Amides to Nitriles under Conditions of a Catalytic Appel Reaction
Shipilovskikh, Sergei A.,Vaganov, Vladimir Yu.,Denisova, Elena I.,Rubtsov, Aleksandr E.,Malkov, Andrei V.
supporting information, p. 728 - 731 (2018/02/09)
A highly expedient protocol for a catalytic Appel-type dehydration of amides to nitriles has been developed that employs oxalyl chloride and triethylamine along with triphenylphosphine oxide as a catalyst. The reactions are usually complete in less than 10 min with only a 1 mol % catalyst loading. The reaction scope includes aromatic, heteroaromatic, and aliphatic amides, including derivatives of α-hydroxy and α-amino acids.
Palladium-Catalyzed Site-Selective Fluorination of Unactivated C(sp3)-H Bonds
Miao, Jinmin,Yang, Ke,Kurek, Martin,Ge, Haibo
supporting information, p. 3738 - 3741 (2015/08/18)
The transition-metal-catalyzed direct C-H bond fluorination is an attractive synthetic tool toward the preparation of organofluorines. While many methods exist for the direct sp3 C-H functionalization, site-selective fluorination of unactivated sp3 carbons remains a challenge. Direct, highly site-selective and diastereoselective fluorination of aliphatic amides via a palladium-catalyzed bidentate ligand-directed C-H bond functionalization process on unactivated sp3 carbons is reported. With this approach, a wide variety of β-fluorinated amino acid derivatives and aliphatic amides, important motifs in medicinal and agricultural chemistry, were prepared with palladium acetate as the catalyst and Selectfluor as the fluorine source.
Substituent effects on regioselective intramolecular oxidation of unactivated C-H bonds: Stereoselective synthesis of substituted tetrahydropyrans
Wong, Man-Kin,Chung, Nga-Wai,He, Lan,Yang, Dan
, p. 158 - 162 (2007/10/03)
Our previously reported intramolecular δ-selective C-H bond oxidation by dioxiranes, generated in situ from activated ketones, offers a novel approach to the synthesis of tetrahydropyrans. To synthesize substituted tetrahydropyrans in a stereoselective manner, we examined the effects of alkyl, nitrogen, and oxygen substituents at the α-,β-, and γ-sites of ketones on the stereoselectivities of intramolecular C-H bond oxidation reactions. Ketones 1-4 with a methyl group at the α-, β-, or γ-site showed the diastereo-selectivities that agreed with the trans/cis ratio predicted by considering steric interactions in the transition states. Furthermore, ketones 5 and 6 carrying a bulky phthalimido group at the α- and the β-sites, respectively, exhibited excellent stereoselectivity, each affording only one diastereomer. However, ketones 9 and 10 bearing β-oxygen substituents gave reversed stereoselectivity as compared to those with β-alkyl or nitrogen substituents, possibly because of the hydrogen bonding interaction in the transition state. For ketones 12 and 13, both bearing methyl and silyloxy groups, the hydrogen bonding interaction was probably more important than the steric effect on the diastereoselectivity of intramolecular oxidation of C-H bonds.
