Organometallic compounds

Mo2O3(Et2dtc)2(THF) 2I2 (1) reacts with a variety of oxygen atom donor substrates, X-O, such as pyridine-N-oxides, sulfoxides and nitrate to produce MoO2^2+ complexes and X by oxygen atom transfer. Results from kinetics studies indicate the formation of a (1)-substrate intermediate that decomposes to form the products. The lifetime of the intermediate apparently depends on the stability of the leaving group, X. Since the R-group in nitroso compounds, R-N=0, would not be stable leaving groups the (1)-nitroso complex might be expected to be quite long lived or even stable. Indeed, reaction of (1) with nitroso compounds such as nitrosobenzene produce stable molybdenum-oxaziridines which have been identified using 1H-NMR, IR and electronic spectral data. The use of these complexes in the mediation of allylic amination reactions was studied.

A large number of metal-containing compounds show significant activity against cancer cells and incorporating a metal into a polymer offers several possible advantages. Compounds of the type R2SnCl2 (R = methyl, ethyl, propyl, butyl, t-butyl, octyl and phenyl) were tested for the ability to inhibit the growth of Balb 3T3 mouse fibroblast cells and CAOV3 human ovarian carcinoma cells. Polymers of 2-chloro-1,4-benzenediamine and the same organotin dichloride were synthesized and tested as well. For both monomers and polymers, the pattern of growth inhibition relative to the R group was butyl > propyl = t-butyl = octyl = phenyl > ethyl > methyl. This and other aspects of the structure-activity relationship of the monomers and polymers were examined.

The conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement reaction involved an intermediate cumenolate. It was also confirmed that amine base with pKa lower than that of DBU (pKa = 13.6) would not carry out the isomerization. Alkoxy base were also used in isomerization and the mechanism was also investigated.