A library of forty modified aminoglycosides was prepared in which the configuration and regiochemistry of two or three rings was widely varied. The library was based around three core ring systems: the 2-deoxystreptamine ring system found in the natural products, and both enantiomers of (1R*,2R*,4R*,5R*)-2,5-diamino-cyclohexane-1,4-diol and (1R*,3R*,4R*,6R*)-4,6-diaminocyclohexane-1,3-diol. In ...

The reaction of the phosphonium alkylidene [(H(2)IMes)RuCl(2)=CHP(Cy)(3))](+) BF(4)(-) with propene, 1-butene, and 1-hexene at -45 °C affords various substituted, metathesis-active ruthenacycles. These metallacycles were found to equilibrate over extended reaction times in response to decreases in ethylene concentrations, which favored increased populations of α-monosubstituted and α,α'-disubst...

In the title compound, C(22)H(17)NO(5)S(2), the dithiole and oxindole rings are almost coplanar [dihedral angle = 2.71 (8)°] and the phenyl ring makes a dihedral angle of 73.65 (5)° with the oxindole ring. Inter-molecular π-π contacts between adjacent oxindole and dithiole rings [centroid-centroid distance = 3.7273 (11) Å] stabilize the crystal packing.

In the title compound, C(23)H(19)NO, the oxindole residue is essentially planar and is almost perpendicular to the phenyl rings [dihedral angles = 72.1 (6) and 77.6 (6)°]. The mol-ecular packing is stabilized by C-H⋯O hydrogen bonds and C-H⋯N inter-actions.

Both flash vacuum thermolysis (FVT) and matrix photolysis generate 2-diazomethylpyrazine (22) from 1,2,3-triazolo[1,5-a]pyrazine (24). FVT of 4-azidopyridine (18) as well as of 24 or 2-(5-tetrazolyl)pyrazine (23) affords the products expected from the nitrene, i.e., 4,4'-azopyridine and 2- and 3-cyanopyrroles. Matrix photolyses of both 18 and 24 result in ring expansion of 4-pyridylnitrene/2-py...

A ring is called clean if every element is the sum of a unit and an idempotent. Throughout the last 30 years several characterizations of commutative clean rings have been given. We have compiled a thorough list, including some new equivalences, in hopes that in the future there will be a better understanding of this interesting class of rings. One of the fundamental properties of clean rings i...

Abstract This study reports the development of Rh(II)-catalyzed N–N bond-forming reaction amino acid derivatives or aliphatic amines to provide hydrazine through combined use Rh2(esp)2 and [(3,4-dimethoxyphenyl)sulfonylimino]-2,4,6-trimethylphenyliodinane (3,4-(MeO)2C6H3SO2N=IMes). is first report N–H amination with metal–nitrene species.