Refernces
10.3987/com-07-s(w)7
The research focuses on the synthesis and reactions of 3-ethynyl-2-(triphenylphosphoimino)-1-azaazulenes, specifically the compounds with trimethylsilylethynyl and phenylethynyl groups. The main reactions involve the Appel reaction to synthesize the target 1-azaazulenes and subsequent reactions with copper catalysts, such as Cu(OTf)2, to achieve oxidation of the ethynyl group, leading to the formation of various complex heterocycles. The study also explores the reaction of these compounds with aryl isocyanates in the presence of benzoyl peroxide, resulting in 1,10-diazabenz[a]azulene derivatives. The reactants include 2-amino-3-ethynyl-1-azaazulenes, PPh3, hexachloroethane, Et3N, and various Lewis acids. The analyses used to characterize the synthesized compounds and intermediates encompass spectroscopic techniques (NMR, IR, and UV-Vis), elemental analysis, and X-ray structure determination for compound 13, which provided crucial evidence for the structural assignments and the nature of the reactions involved.
10.1139/V08-072
The study focuses on the photochemistry of trans-isohumulone, a key bitter flavoring component in beer, to understand its degradation under UV light, which is crucial for the brewing industry. The researchers irradiated methanolic solutions of trans-isohumulone with UV light at 313 nm, yielding four primary products containing an enolized cyclic β-triketone moiety: cis-isohumulone, humulone, dehydro-isohumulone, and dehydro-humulinic acid. Nine volatile products derived from the side chain of trans-isohumulone were also identified and quantified. The study aimed to clarify previous contradictory reports on the photolysis products of isohumulone and to provide insights into the unexpected photochemistry of alkenyl-substituted enolized cyclic β-triketones. The chemicals used in the study served as solvents, reagents for the irradiation process, and standards for the identification and quantification of the photoproducts.
10.1080/10426500802101109
The study investigates the synthesis of a series of new 2-substituted tetrahydrobenzo[4′,5′]thieno[3,2:5,6]pyrido[4,3-d]pyrimidin-4(3H)-ones using an aza-Wittig reaction. The key chemicals involved include iminophosphoranes (3a and 3b), which are derived from tetrahydrobenzo[4,5]thieno[2,3-b]pyridines (2a and 2b) through a reaction with triphenylphosphine, hexachloroethane, and Et3N. These iminophosphoranes react with 4-Cl-phenyl or 4-F-phenyl isocyanates to form carbodiimides (4a and 4b). In the presence of a catalytic amount of K2CO3, these carbodiimides cyclize with phenols to produce the target compounds (5). The study explores the synthesis process, yields, and structural confirmation of these compounds using techniques such as 1H NMR, EI-MS, IR spectroscopy, and elemental analyses. The research aims to explore the potential biological activities of these novel pyridine derivatives containing the thienopyridine and pyridopyrimidine rings.
10.1055/s-1987-28108
The study presents a simple one-pot procedure for generating nitrilimines from N-acyl hydrazines using a halogenating-dehydrohalogenating system comprising triphenylphosphane, hexachloroethane, and triethylamine, via dichlorotriphenylphosphoranes. The in situ generated diphenylnitrilimine undergoes 1,3-dipolar cycloadditions with various dipolarophiles like ethyl acrylate and norbornene, yielding cycloadducts such as pyrazolines and pyrazoles. Additionally, 1,5-electrocyclizations of conjugated nitrilimines linked to heterocycles with suitable double bonds produce complex multicondensed heterocyclic systems. This method is advantageous due to the easy access to starting materials, straightforward reaction steps, and avoidance of contact with allergenic and skin-irritating hydrazonyl halides.
Xn, 
N, 
T, 
F
Xn:Harmful;
