Debra D. Dolliver

Stereospecific Suzuki, Sonogashira, and Negishi Coupling Reactions of N-Alkoxyimidoyl Iodides and Bromides

A high-yielding stereospecific route to the synthesis of single geometric isomers of diaryl oxime ethers through Suzuki coupling of N-alkoxyimidoyl iodides is described. This reaction occurs with complete retention of the imidoyl halide geometry to give single E- or Z-isomers of diaryl oxime ethers. The Sonogashira coupling of N-alkoxyimidoyl iodides and bromides with a wide variety of terminal alkynes to afford single geometric isomers of aryl alkynyl oxime ethers has also been developed. Several of these reactions proceed through copper-free conditions. The Negishi coupling of N-alkoxyimidoyl halides is introduced. The E and Z configurations of nine Suzuki-coupling products and two Sonogashira-coupling products were confirmed by X-ray crystallography.

Bisamidoximes: Synthesis and Complexation with Iron(III)

Bisamidoximes have been synthesized by the reaction of 4-methylbenzohydroximoyl chloride with 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, and 3,3′-diamino-N-methyl-dipropylamine. A monoamidoxime and a trisamidoxime were also prepared in the present work by the reaction of 4-methylbenzohydroximoyl chloride with N,N-dimethylethylenediamine and tris(2-aminoethyl)amine. Single crystal X-ray structures of three of the bisamidoximes have shown that the two amidoxime moieties have the Z configuration in all three compounds. Job’s method of continuous variations showed that three of the bisamidoximes prepared in this work form 1:1 complexes with iron(iii) and therefore are acting as tetradentate ligands.

Synthesis and Characterization of α,β-Unsaturated Hydroximoyl Chlorides and Hydroximates

New α,β-unsaturated hydroximoyl chlorides (PhC(Cl)=CHC(Cl)=NOCH3) and hydroximates (PhC(OCH3)=CHC(OCH3)=NOCH3) were prepared. The ZZ-isomer of PhC(Cl)=CHC(Cl)=NOCH3 was prepared in four steps from ethyl benzoylacetate. Ultraviolet irradiation of the ZZ-isomer gives a mixture of all four possible isomers. Sodium methoxide was reacted with these isomers to determine the configuration about the carbon–carbon double bond for each. The Z-isomers reacted with sodium methoxide to give the corresponding alkyne by elimination whereas the E-isomers gave the substitution product. The configuration about the carbon–nitrogen double bond was determined from the 1H NMR chemical shift of the NOCH3 group.