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Polymerization
Published in Rudolf Puffr, Vladimír Kubánek, Lactam-Based Polyamides, 2019
The same process is operative in the hydrolytic ring-opening Reaction 37 and similar tetrahedral intermediates are formed in the acid catalyzed reaction of the lactam amide group with the primary amine group (Reaction 39) as in the cationic process 28 (see Section III.B.2). Whereas C–N cleavage leads to the incorporation of one lactam molecule, C–O cleavage yields water and amidine groups. A similar reaction with a polymer amide group yields amidine groups 9 representing sites of branching:
Microwave-Assisted Transition Metal-Catalyzed Synthesis of Pharmaceutically Important Heterocycles
Published in Banik Bimal Krishna, Bandyopadhyay Debasish, Advances in Microwave Chemistry, 2018
Dipti Shukla, Priyank Purohit, Asit K. Chakraborti
Cho and co-workers [83] reported a tandem aromatic nucleophilic substitution-amide formation for the synthesis of pyrimidinones 114 from the reaction of β-bromo α,β-unsaturated 112 carboxylic acid with amidine hydrochlorides 113 in the presence of catalytic amounts of copper-powder and base under microwave heating (Scheme 9.41).
Interaction of Polymer Latices with Other Inorganic Colloids
Published in Kunio Esumi, Polymer Interfaces and Emulsions, 2020
The experiments were carried out with latex microspheres of positive surface potential. The only functional group present on the particle surfaces is the amidine group (C(NH2)=NH2+)[27].
Synthesis of helical branched carbodiimide polymers with liquid crystalline properties
Published in Liquid Crystals, 2022
Enosha Harshani De Silva, Bruce M. Novak
Helical polycarbodiimides are a class of rigid rod-like polymers consisting of the nitrogen-rich backbone and various sidechains. Typically, they are synthesised in a living fashion through Ti(IV)-catalysed polymerisation [1–3]. The alternating imine and amine nitrogen atoms within the amidine repeat units can possess the same or different side-chains. These versatile polymers have shown interesting properties that lead to their potential use in applications including chiral stationary phases [4], molecular data storage [4,5], liquid crystalline displays [5], anti-microbial agents [6], chiroptical switches [4,5], and asymmetric solid supports [7]. In addition, these functional groups also determine the solubility [1,3,6–8], dihedral angle [1,3,6–8], helical pitch [1,3,6–8], helical inversion barrier [1,3,6–8], and regioregularity [1,3,6–8] of the polymer.
Rhodium catalysis in the synthesis of fused five-membered N-heterocycles
Published in Inorganic and Nano-Metal Chemistry, 2020
Navjeet Kaur, Neha Ahlawat, Yamini Verma, Pranshu Bhardwaj, Pooja Grewal, Nirmala Kumari Jangid
The substrate scope was improved with the formation of lactam utilizing aryl alkynes (207). The carbodiimide (208) was utilized in place of isocyanate.[158] Exchange of the isocyanate for the carbodiimide (208) biases oxidative cyclization toward metallacycle which allowed the lactam formation selectively even with vinylogous amide-favoring aryl alkynes (Scheme 49). This preference was partially override due to electron-rich alkynes. The amidine products were modified upon the reduction of imine to amine or hydrolysis to afford the lactam, illustrating their synthetic utility.[153]