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Recycling of Automotive Plastics
Published in Rose A. Ryntz, Philip V. Yaneff, Coatings Of Polymers And Plastics, 2003
6. Aziridine (ethylene imine) crosslinking has been utilized extensively in the coating of interior, low heat-distortion temperature plastics because of its capability to crosslink under ambient conditions. Aziridine reacts with acids to form 2-hydroxyamides, which can further rearrange to the acid salt of 2-aminoester. Polyfunctional aziridines are generally achieved through the Michael addition of 3 moles of aziridine with 1 mole of trimethylol propane triacry-late. Polyaziridines can be formulated in water but usually only as two-pack systems. The pH is adjusted on the order of 8.5 to 9 to control the reactivity ratio of aziridine/carboxylic acid versus the competitive reaction with water. A major problem associated with aziridine, however, is the monomer's high toxic-ity and carcinogenicity.
N-Heterocycles
Published in Navjeet Kaur, Metals and Non-Metals, 2020
Various multi-component reactions have explored and increased the diversity of compounds and reaction speeds. For macrocyclization of linear peptides, aziridine aldehyde dimers have been utilized in the multi-component Ugi reaction. Zinc acetate-catalyzed multi-component aldehyde-amine-alkyne couplings with aziridine aldehydes have been investigated for the synthesis of densely functionalized propargyl amino aziridines in good yields and with upto 20:1 diastereoselectivity (Scheme 109) [277].
The coordination of a multidentate NxOy-donor (x and y ≤ 2) oxazolidine-based ligand with Cd(II) and Hg(II); Structural, spectral, and theoretical studies
Published in Journal of Coordination Chemistry, 2018
Zahra Mardani, Vali Golsanamlou, Saba Khodavandegar, Keyvan Moeini, Alexandra M. Z. Slawin, J. Derek Woollins
Several substituted oxazolidines have been investigated extensively because of their importance as pharmacologically active compounds (such as antidiabetic [1], anticonvulsant [2], antitubercular [3], and aldose reductase inhibitors [4]), chiral auxiliaries in the synthesis of a variety of chiral compounds, chain-protecting groups for amino alcohols [5,6], crosslinking agents [7] for the stabilization of collagen [8,9], linkers in solid-phase synthesis of peptide aldehydes processes [10], optical probe applications [11] and fungicidal activities [12]. Usually, 1,3-oxazolidines are synthesized by the condensation of 1,2-amino alcohols with carbonyl compounds [13]. Some other approaches found in the literature include double-Michael reactions of acetylenes and β-amino alcohols [14], aza-Wacker type reaction of β-amino alcohols with alkenes [15], aziridines with vinyl arenes [16] and tandem ring-opening/closing reaction of aziridine itself [16]. One other method is the ring formation process from α-hydroxyesters [17] or α-hydroxyamides [18] by treatment with a reagent already carrying the carbonyl function and α-hydroxycarboxylic acids with carbodiimide [19].
Regio- and stereo-selective ring expansion of keto-aziridines to the corresponding thiomorpholines
Published in Journal of Sulfur Chemistry, 2021
Fatemeh Khodadadi, Heshmat Allah Samimi, Jalal Albadi, Ahmadreza Momeni
The proposed mechanism is supported with the fact that our previous work [29,30] showed iodide attack to C-2 of N-acyl aziridines to make a C–N bond breaking of aziridine ring. According to our result, when KI was not present (Scheme 4), C3-N bond will break by front-side attack of the sulfur directly on the ring carbon of aziridine of intermediate B to break the C–N bond (i.e. the SNi mechanism) to produce 3a. While in the presence of KI (Scheme 5), iodide as a good nucleophile will react with both C2 and C3 to form intermediate C and D, subsequently via an intramolecular reaction gives compounds 4a and 3a.