Rudolph K. Kullnig

Synthesis and structure of bis(1,1-diethyl-3-(2-chlorobenzoyl)thioureido)nickel(II)

Abstract The Ni(II) complex of 1,1-diethyl-3-(2-chlorobenzoyl) thiourea (L) was synthesized and its crystal structure determined by X-ray crystallography. NiL2 is monoclinic, space group P2l/c(#14), with a=8.229, b=39.277, c=8.485 A, β=96.8°. The Ni(II) is coordinated in a planar fashion by two S and two O atoms in a cis arrangement. The NiS and NiO bond lengths are approximately 2.14 and 1.84 A respectively, with the two bonds of each type differing only slightly. The SNiS and O NiO bond angles are 87.6° and 83.0° respectively, but with considerable expansion of the ligand bond angles in the chelate ring. The crystal structure of the free ligand was also determined to compare free and complex bond lengths and angles. It is orthorhombic, space group Pbca(#61), with a=9.856, b=10.128 and c= 26.848 A.

Photochemistry of 1-carbomethoxy-6-methyltricyclo[4.3.1.04,6]dec-2-en-10-one. Preparation of a 1,3-cyclooctadiene

Abstract The preparation and photorearrangements of pyrazoline 7 and vinylcyclopropane 8 are described.

Bimetallic acetyl complexes: (η5-indenyl)2(CO)3Fe2(COCH3)− and (η5-indenyl)(η5-Cp)(CO)3Fe2(COCH3)−: their role in a novel carbonylation reaction

Abstract Treating alkly(η5-indenyl) iron complexes In(CO)2FeR (R  CH3, CH2OCH3) with either nucleophilic metalate Cp(CO)2Fe−Na+ (CP  η5-C5H5) or In(CO)2Fe−Na+ affords stable bimetallic complexes In(CO)Fe (η-CO)2Fe(In)- (COCH3)−Na+ (3) and (In)(Cp)(CO)3Fe2(COR)−Na+ (4, R  CH3; 9, R  CH2OCH3). The fully characterized PPN+ salts 3 and 4 (PPN  Ph3PNPPh3) both retain cis-structures having terminal (η1) acyl ligands. Compound 4 exists as a 1 1 mixture of isomers corresponding to the acetyl group at alternate iron centers: results of 1H NMR magnetization transfer experiments further established that these isomers slowly equilibrate at room temperature. X-ray structural determination of 4PPN+ showed that it crystallizes as the isomer having the acetyl coordinated on the CpFe end. These binuclear acyl products readily fragment (1 atm CO, R′X) into mononuclear acyl products, Cp(CO)2FeCOCH3 and Cp(CO)2FeCOCH2-OCH3 from 4 and 9, respectively, and In(CO)2FeCOCH3 from 3. By-products include In(CO)2FeR′ (R′  CH3, CH3CH2, Ph3Sn) and, depending on the reaction conditions, binuclear vinylidene compounds. A reaction pathway is proposed that accounts (by invoking reversible η5/η3-In ligand shifts) for the regioselective cleavage and carbonylation of 4 and 9 to their mononuclear Cp(CO)2Fe-acyl products.

Intramolecular reactions of 2-(azidobutyl)-1,4-benzoquinones. Unexpected rearrangement to a furo[3,4-b]indolizidine-2-one

Abstract Thermal rearrangements of 2-(azidobutyl)-1,4-benzoquinone 1 give 3 and 4 , while that of 10 produces ring-contracted 12 ; thermolysis of 12 gives ring-expanded 15 .

Acid-catalyzed rearrangement of methyl (2aα,4aβ,6aβ,7bβ)-2,2a,5,6,6a,7b-hexahydro-2a-hydroxy-4-methoxycyclobut[3,4] indeno[4,5-b]oxete-4a(7H)-carboxylate

Abstract Acid-catalyzed rearrangement of 3 gives isomeric β-methoxyketone 9a , presumably via the intermediate bridgehead enone 8 .