32704-22-6Relevant articles and documents
Easy Access to Crystalline Indolines via Hydrogen Bond Transfer
Khatoon, Saira,Vgenopoulou, Aggeliki,Naseer, Muhammad Moazzam,Shirinfar, Bahareh,Kariuki, Benson M.,Dege, Necmi,Ahmed, Nisar
, p. 1388 - 1392 (2019)
Several indoline derivatives with specific geometries are biologically active and have inhibitor properties. Many indolines are a key part of natural products. Much attention has been focused on the development of synthetic routes for their easy access. C
Regioselective Radical Arene Amination for the Concise Synthesis ofortho-Phenylenediamines
Gillespie, James E.,Morrill, Charlotte,Phipps, Robert J.
supporting information, p. 9355 - 9360 (2021/07/19)
The formation of arene C-N bonds directly from C-H bonds is of great importance and there has been rapid recent development of methods for achieving this through radical mechanisms, often involving reactiveN-centered radicals. A major challenge associated with these advances is that of regiocontrol, with mixtures of regioisomeric products obtained in most protocols, limiting broader utility. We have designed a system that utilizes attractive noncovalent interactions between an anionic substrate and an incoming radical cation in order to guide the latter to the areneorthoposition. The anionic substrate takes the form of a sulfamate-protected aniline and telescoped cleavage of the sulfamate group after amination leads directly toortho-phenylenediamines, key building blocks for a range of medicinally relevant diazoles. Our method can deliver both free amines and monoalkyl amines allowing access to unsymmetrical, selectively monoalkylated benzimidazoles and benzotriazoles. As well as providing concise access to valuableortho-phenylenediamines, this work demonstrates the potential for utilizing noncovalent interactions to control positional selectivity in radical reactions.
Catalytic C(sp2)?H amination reactions using dinickel imides
Andjaba, John M.,Powers, Ian G.,Uyeda, Christopher,Zeller, Matthias
supporting information, p. 3794 - 3801 (2020/11/23)
C?H amination reactions are valuable transformations for the construction of C?N bonds. Due to their relatively high bond dissociation energies, C(sp2)?H bonds are generally not susceptible toward direct nitrene insertion, necessitating alternative mechanisms for C?H activation. Here, we report that cationic dinuclear (NDI)Ni2 (NDI = naphthyridine?diimine) complexes catalyze intramolecular nitrene insertions into aryl and vinyl C(sp2)? H bonds. Mechanistic studies suggest that a bridging imido ligand supported at a Ni2 site induces C?H activation by a 1,2-addition pathway to generate an azametallacyclic intermediate. This organometallic mechanism contrasts with the electrocyclization/1,2-shift mechanism proposed for analogous transformations using Rh2 catalysts. The implications of these mechanistic differences for the stereoselectivity and chemoselectivity of C?H amination are described.
Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
supporting information, (2020/05/18)
The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
