With the new chiral phosphine ligand DBUP, obtained from DBU and Ph(2)PCl, a remarkable anion effect was observed on the diastereoselective formation of the bischelated complexes [Ni(DBUP)(2)](X)(n) (X = Cl, Br, n = 2; X = NiCl(4), n = 1), which are active ethylene oligomerization catalyst precursors.

This account summarizes the results of mechanism studies on the nitrile-forming eliminations from (E)and (Z)-arylaldehyde O-benzoyloximes promoted by 1,8-diazabicyclo-[5.4.0]undec-7ene (DBU) in MeCN, R1R2NH in MeCN, and R1R2NH/R1R2NH2 in 70mol% MeCN(aq). The rate of anti-elimination was 36,000-fold faster than that of syn-elimination. The change of the βaryl group from Ph to thienyl to furyl sh...

A facile method for the introduction of various substituents at the C-6 position of guanosine and 2'-deoxyguanosine is reported. In a simple, 1-step transformation, tert-butyldimethylsilyl protected guanosine and 2'-deoxyguanosine were converted to the O(6)-(benzotriazol-1-yl) derivatives via reaction with 1H-benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1,8-...

Enyne alcohols can react as precursors of either dienes or dienophiles with different substrates after hydroxylation and isomerization by gold catalysis. As such, oxa-bridged tricyclo[5.2.2.02,6]-undec-8-ene-3,5-dione derivatives have been obtained by the Diels–Alder reaction and tetrahydro-1H-furo[3,4-c]pyran derivatives could be accessed by the hetero-Diels–Alder cycloaddition.

The title compound, C15H17NO2, was synthesized from a mixture of α-himachalene (2-methyl-ene-6,6,9-tri-methylbi-cyclo-[5.4.0(1,7)]undec-8-ene) and β-himachalene (2,6,6,9-tetra-methylbi-cyclo-[5.4.0(1,7)]undeca-1,8-diene), which were isolated from an oil of the Atlas cedar (Cedrus Atlantica). The naphthalene ring system makes dihedral angles of 68.6 (2) and 44.3 (2)°, respectively, with its atta...

The title compound, C(15)H(16)N(2)O(4), was synthesized from a mixture of α-himachalene (2-methyl-ene-6,6,9-trimethyl-bicyclo-[5.4.O(1,7)]undec-8-ene) and β-himachalene (2,6,6,9-tetra-methyl-bicyclo-[5.4.0(1,7)]undeca-1,8-diene) which were isolated from an oil of the Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent mol-ecules. In each of the two mol-ecules, two O ato...

Substituted thiazolo ring-fused 2-pyridones, called pilicides, possess novel antibacterial properties and inhibit pilus assembly in Uropathogenic Escherichia coli. Recently, a small number of oxygen analogues of active pilicides have shown maintained ability to disrupt pilus assembly. Here an improved methodology for the synthesis of oxazolo ring-fused 2pyridones is presented, allowing dihydro ...