RESUMEN
Herein, we describe a [2+1] annulation reaction of di/trifluorodiazoethane with (alkylidene)malononitriles. This protocol offers a streamlined synthesis of a wide range of stereospecific and densely functionalized difluoromethyl and trifluoromethyl cyclopropane-1,1-dicarbonitriles. Further functional group interconversions or skeletal elaborations afford structurally distinct cyclopropyl variants.
RESUMEN
A diethylzinc-promoted unconventional annulation reaction of 2,2,2-trifluorodiazoethane with 2H-azirines is described. This transformation involves two [3 + 2] cycloaddition steps and one dinitrogen extrusion process in one pot, thus giving a broad array of 3-trifluoromethyl pyrazolines in good yields with excellent diastereoselectivities. Further transformations provide facile access to 3-trifluoromethyl pyrazoles and 3,5-ditrifluoromethyl pyridazines with good efficiency.
RESUMEN
An alkaliphilic actinobacterium, designated EGI 80050(T), was isolated from a desert soil sample of Xinjiang, north-west China, and characterized by a polyphasic approach. The isolate was observed to produce purple orange-yellow aerial mycelium and dark orange-yellow substrate mycelium on yeast extract-malt extract agar medium. Whole-cell hydrolysates of strain EGI 80050(T) were found to contain LL-diaminopimelic acid as the diagnostic diamino acid, and galactose, glucose, rhamnose and mannose as the main sugars. The major fatty acids identified were C16:0-iso (36.8 %), C15:0-anteiso (17.3 %), 15:0-iso (13.2 %) and 14:0-iso (10.5 %). The predominant menaquinones detected were MK-9(H6) and MK-9(H8), while the characteristic polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, phosphatidylmethylethanolamine and three unknown phospholipids. The G+C content of the genomic DNA was determined to be 67.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences affiliated the strain EGI 80050(T) to the genus Streptomyces. Levels of 16 rRNA gene sequence similarities between strain EGI 80050(T) and Streptomyces candidus NRRL ISP-5141(T), Streptomyces cremeus NBRC 12760(T), Streptomyces spiroverticillatus NBRC 12821(T), Streptomyces violaceorectus NBRC 13102(T), Streptomyces cinereoruber subsp. cinereoruber NBRC 12756(T) were 96.7, 96.6, 96.6, 96.6 and 96.6 %, respectively. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain EGI 80050(T) is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces fukangensis sp. nov. (type strain EGI 80050(T) = BCRC 16945(T) = JCM 19127(T)) is proposed.