I. An unusually rapid intramolecular general-base catalysis. Relevance to enzymology. II. Applications of light microscopy in the study of giant vesicles. An introduction to cytomimetic organic chemistry

Part I. 4,4-Bis(phenylsulfonyl)-2-methylbutylamine (I) undergoes an intramolecular amine-catalyzed exchange of its acidic methine proton. The rate of exchange in toluene-{dollar}dsb8{dollar} is too fast to measure by NMR at {dollar}sp-80spcirc{dollar}C. In contrast, the corresponding intermolecular-catalyzed reaction is too slow to measure by NMR at {dollar}sp+100spcirc{dollar}C. Since the effective molarity (i.e. {dollar}rm ksb{lcub}intra{rcub}/ksb{lcub}inter{rcub}{dollar}) of an intramolecular general base catalysis seldom exceeds 20M, the unprecedented rate difference between our intramolecular and intermolecular processes warranted a detailed mechanistic investigation. It can be argued that the intramolecular catalyzed exchange is assisted by a tight hydrogen bond between the amine and the carbon acid proton. This is supported by evidence that the N-to-H distance in the analogous tertiary amine is actually less than the sum of the van der Waal radii of the two atoms. According to the "spatiotemporal hypothesis", this gives the intramolecular process an enormous kinetic advantage over the intermolecular counterpart. These results may be relevant to fast proton transfer at the active sites of enzymes.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI); Part II. The recent developments in preparing giant unilamellar vesicles (GUVs) has led to new approaches for studying membrane behavior. The development of the light microscope as a powerful tool for studying vesicle behavior is described. Investigations of various complex membrane processes such as fusion, fission, exocytosis, endocytosis, and translocation will be discussed. Some control over these membrane processes has been attained using a vesicle system comprised of a synthetic lipid; didodecyldimethylammonium bromide (DDAB) (I). A new method for preparing GUVs using DDAB will be presented. The effects of various chemical additives as well as the physical manipulation of DDAB GUVs will be discussed as well as illustrated through the use of numerous photomicrographs. The work which follows describes an area of research in its 'infant' stages but it is apparent, based on the preliminary results, that the light microscope is a viable tool for the organic chemist and will lead to new insight into a dynamic system.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)...