Narrow Results

Iron(III) tetraphenylporphyrin chloride, Fe(TPP)Cl, efficiently catalyzed the insertion of carbenes derived from methyl 2-phenyldiazoacetates into O-H bonds of aliphatic and aromatic alcohols, with yields generally above 80%. Although the analogous N-H insertions are rapid at room temperature, the O-H insertion reactions are slower and required heating in refluxing methylene chloride for about 8 hours using 1.0 mol.% catalyst. Fe(TPP)Cl was also found to be effective for tandem N-H insertion/cyclization reactions when 1,2-diamines and 1,2-alcoholamines were treated with diazo reagents to give piperazinones and morpholinones and related analogs such as quinoxalinones and benzoxazin-2-ones. This approach provides a new one-pot route for synthesizing these classes of heterocyclic compounds.

Ruthenium-catalyzed protocols play an important role in the synthesis of five-membered heterocycles. An overview of reported examples in this field will be discussed in this chapter, including mechanism presentations for some typical transformations.

In this paper, an unsymmetrical photochromic diarylethene called 1-[2-methyl-5-(4-propylphenyl)-3-thienyl]-2-[(2-methyl-5-acetylenyl)-3-thienyl] perfluorocyclopentene was synthesized and its photochromic properties such as photochromism in hexane solution and reaction kineticswere analyzed. The diarylethene has demonstrated good photochromic behavior and fluorescent switching in solution. Upon irradiation with UV and Vis light, the diarylethene underwent reversible cyclization and cycloreversion reactions.

A novel heterocyclic compound with pendent spiro-cyclotriphosphazene group was designed and synthesized via a convenient synthetic pathway. The structure was characterized by Fourier transform infrared spectroscopy(FTIR), Nuclear magnetic resonance (¹H NMR), Liquid chromatograph mass spectrometer (LC-MS). The incorporation of phosphazene rings into the molecular backbone imparts flame retardancy on the compound. This may result from a unique combination of phosphorus and nitrogen in the phosphazene ring. The compound synthesized in this study is a green functional monomer and may become a potential candidate for fire- and heat-resistant applications in polymer fields.