Synthesis and Photochemical Study of Thiazolidine Derivatives of Cymantrene and the Corresponding Dicarbonyl Chelates

Isomeric 4,5-dihydro-2-[(cymantrenylmethyl)thio]thiazole (1) and 3-(cymantrenylmethyl)-1,3-thioazolidine-2-thione (2) were synthesized and photochemical behavior and spectral characteristics of tricarbonyl and dicarbonyl complexes were studied. Irradiation of compounds 1 and 2 results in the formation of stable chelates due to coordination of manganese to the donor nitrogen and sulfur atoms of the thiazolidine substituent. Photolysis is accompanied with a colour change and the corresponding changes in the UV/Vis spectra depending on the solvent used. In the presence of CO, the dicarbonyl chelates enter the dark reaction to give the parent tricarbonyl complexes thus forming intermolecular photochromic systems. Photolysis of the dicarbonyl chelate 5 gives the isomeric chelate 6, which in the course of the dark isomerization transforms into complex 5. Chelates 5 and 6 form an intramolecular photochromic pair. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Synthesis, molecular structure and photochemical properties of tricarbonyl and dicarbonyl derivatives of 1N- and 2N-cymantrenylalkyl-1,2,3-triazoles

1N- and 2N-cymantrenylalkylsubstituted 1,2,3-triazoles were for the first time synthesized. It was found that irradiation by a mercury lamp light with λ = 365 nm of cymantrenylalkyl-1,2,3-triazoles 3, 5–8 gives stable dicarbonyl chelates 4, 9–12. In a closed system without CO removal, intermolecular photochromic systems between tricarbonyl and dicarbonyl complexes were formed; half-conversion time for the dark reaction was more than 10 h. The effect of a substituent position in dicarbonyl chelates 4, 9–12 on the parameters of their spectra, coordination ability of the N atom and chemical stability was studied. It was found that coordination ability of the nitrogen atoms markedly depends on steric hindrances, which are significantly different in 1N- and 2N-substituted triazoles. © 2017 Elsevier B.V

Synthesis, molecular structure and photochemical properties of tricarbonyl and dicarbonyl derivatives of 1N- and 2N-cymantrenylalkyl-1,2,3-triazoles

1N- and 2N-cymantrenylalkylsubstituted 1,2,3-triazoles were for the first time synthesized. It was found that irradiation by a mercury lamp light with λ = 365 nm of cymantrenylalkyl-1,2,3-triazoles 3, 5–8 gives stable dicarbonyl chelates 4, 9–12. In a closed system without CO removal, intermolecular photochromic systems between tricarbonyl and dicarbonyl complexes were formed; half-conversion time for the dark reaction was more than 10 h. The effect of a substituent position in dicarbonyl chelates 4, 9–12 on the parameters of their spectra, coordination ability of the N atom and chemical stability was studied. It was found that coordination ability of the nitrogen atoms markedly depends on steric hindrances, which are significantly different in 1N- and 2N-substituted triazoles. © 2017 Elsevier B.V

Synthesis of N,N′-Dialkylated Cyclohexane-1,2-diamines and Their Application as Asymmetric Ligands and Organocatalysts for the Synthesis of Alcohols

A series of N,N′-dialkylated derivatives of (1R,2R)-cyclohexane-1,2-diamine were synthesized, and a new approach to the one-pot preparation of this type of amine was demonstrated. The prepared diamines were used as organocatalysts for the two-step synthesis of α-hydroxy γ-keto esters from arenes, chlorooxoacetates, and ketones; they were also used as chiral ligands for Meervein-Ponndorf-Verley reductions and Henry reactions. © Georg Thieme VerlagStuttgart · New York

Synthesis of N,N′-Dialkylated Cyclohexane-1,2-diamines and Their Application as Asymmetric Ligands and Organocatalysts for the Synthesis of Alcohols

A series of N,N′-dialkylated derivatives of (1R,2R)-cyclohexane-1,2-diamine were synthesized, and a new approach to the one-pot preparation of this type of amine was demonstrated. The prepared diamines were used as organocatalysts for the two-step synthesis of α-hydroxy γ-keto esters from arenes, chlorooxoacetates, and ketones; they were also used as chiral ligands for Meervein-Ponndorf-Verley reductions and Henry reactions. © Georg Thieme VerlagStuttgart · New York