A novel synthetic approach towards 2-guanidinomethyl-4(5)-sulfamoylimidazoles

Phosphine–Imidazolyl Ligands for the Efficient Ruthenium‐Catalyzed Hydrogenation of Carboxylic Esters

“…Thus, compound 4 was prepared in high yield (85 %) as a stable and easy to handle powder, whilst compound 3 was commercially available. [10] With a library of different P-N ligands in hand, we tested them in the ruthenium-catalyzed reduction of methyl benzoate (5 a). For convenience, the [RuL 2 Br 2 ] catalyst was generated in situ from [RuA C H T U N G T R E N N U N G (cod)(methylallyl) 2 ] (0.5 mmol) and ligands 1-4 (1 mmol).…”

“…[11] Initial studies on the influence of the experimental conditions on the reaction were carried out with ligand 1 d in the presence of base (10 mol %) in THF. To afford complete conversion within a reasonable length of time, the reaction was performed under 50 bar H 2 at 100 8C (Table 1, (2), C6-P1 1.813(2), C9-P1 1.807(2); C2-P1-C6 112.09(11), C2-P1-C9 108.32(11), C6-P1-C9 113.11 (10). b) ORTEP of compound 1 c·HBr; thermal ellipsoids set at 30 % probability.…”

“…b) ORTEP of compound 1 c·HBr; thermal ellipsoids set at 30 % probability. Selected bond lengths [] and angles [8]: C1-P1 1.869(2), C6-P1 1.853(2), C12-P1 1.852(2); C1-P1-C6 102.26 (10), C1-P1-C12 98.89 (10), C6-P1-C12 103.87 (10). tained in 88 % yield after around 4 h. At 80 8C, the conversion and yield of compound 6 a decreased dramatically and the formation of a significant amount of benzyl benzoate 7 a as a side-product, which was formed by the transesterification of methyl benzoate with benzyl alcohol, was observed (Table 1, entry 4).…”

“…The addition of LiPPh 2 led to displacement of the sulfate group by the PPh 2 moiety. Thus, compound 4 was prepared in high yield (85 %) as a stable and easy to handle powder, whilst compound 3 was commercially available 10…”

Synthesis and properties of DNA containing a spore photoproduct analog

“…All the standard methods based e.g. on treatment of the compounds with fluorides, [19][20][21] bases 22 or acids 23,24 failed. However, we were finally able to cleave the SEM groups in the presence of DNA directly on the solid support with a 1 M SnCl 4 -solution in CH 2 Cl 2 , which was slowly rinsed through the cartridge containing the solid phase material with the DNA attached.…”