294190-47-9Relevant articles and documents
Synthesis of various acylating agents directly from carboxylic acids
Pilathottathil, Fathima,Vineet Kumar, Doppalapudi,Kaliyamoorthy, Alagiri
supporting information, p. 1622 - 1632 (2020/04/27)
A straightforward synthesis of acylating reagents such as Weinreb and MAP amides from aromatic, aliphatic carboxylic acids, and amino acids using PPh3/NBS combination is described. A chemo-selective modification of the carboxylic acid group into Weinreb amide in the presence of more reactive aldehydes and ketones is presented. All reactions were performed at ambient temperature under air using undried commercial grade solvent. Furthermore, the present methodology could be performed at a gram scale under inert-free reaction conditions. In addition, 7-azaindoline amide auxiliary (used for catalytic asymmetric aldol- and Mannich-type reactions), which behaves like Weinreb amide is also synthesized under similar reaction conditions.
Weinreb Amide Directed Versatile C?H Bond Functionalization under (η5-Pentamethylcyclopentadienyl)cobalt(III) Catalysis
Kawai, Kentaro,Bunno, Youka,Yoshino, Tatsuhiko,Matsunaga, Shigeki
supporting information, p. 10231 - 10237 (2018/07/29)
The (η5-pentamethylcyclopentadienyl)cobalt(III) (Cp*CoIII)-catalyzed C?H bond functionalization of aromatic, heteroaromatic, and α,β-unsaturated Weinreb amides was explored. C?H allylation reactions with the use of allyl carbonate and a perfluoroalkene, oxidative alkenylation reactions with the use of ethyl acrylate, iodination reactions with the use of N-iodosuccinimide, and amidation reactions with the use of dioxazolones were catalyzed by Cp*Co(CO)I2 in the presence of a cationic Ag salt and AgOAc to afford various synthetically useful building blocks. Mechanistic studies of the C?H allylation disclosed that the C?H activation step was rate determining and virtually irreversible.
Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides
Das, Riki,Kapur, Manmohan
, p. 1114 - 1126 (2018/06/18)
A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp2)-H functionalization of benzyl nitriles in the presence of activated C(sp3)-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.
