PREPARATION AND AMPHIPHILIC PROPERTIES OF CATIONIC AND AMPHOTERIC POLYMERIZABLE SURFACTANTS DERIVED FROM 5-F-ALKYL 4-OXA 1- DIMETHYLAMINO HEX-5-EN-2-OLS

In this work, we synthesized new reaction intermediates 5-F-alkyl 4-oxa 1-dimethylamino hex-5-en-2-ols which allowed us to obtain, simply and in satisfying yields a broad range of single-chain and double-chain surfactants with two F-alkylated chains or mixed chains, possessing a polymerizable methylene lateral group and at least one hydroxyl function. Their amphiphilic properties were investigated by measuring their surface tension in aqueous solution. The critical micellar concentration (CMC) of some of them could be determined from surface tension curves versus concentration.     

THE PREPARATION AND STABILITY OF COLLOIDAL METAL DISPERSIONS PREPARED BY A TWO-PHASE NON-AQUEOUS ROUTE

Stable suspensions of small metal Au, Ru, PI, Pd, Rh, Co and Nl particles dispersed in n-heptane and n-dodecane have been prepared using a novel two-phase system, Involving the formation of the particles In a methanolic phase and subsequent phase transfer of the panicles to the alkane medium. The dispersions consisted of small particles having diameters In the range of 8-30 nm (the gold sols were very polydlsperse having average diameters of ca.34 nm). The phase transfer of the particles and their subsequent colloid stability were effected by the presence of dissolved dispersant in the hydrocarbon phase (either Oloa 1200 or Hypermer LP 8). In the case of Oloa 1200, a widely-used polylsobutylene succinimide automotive engine dispersant, It Is proposed that the amlne groups adsorb strongly to the acidic surface o1 the particles, and the 70-carbon polyisobutylene chains extend Into the hydrocarbon medium sufficiently to maintain the separation of adjacent particles by steric and possibly also by electrical repulsion.     

N-Bromosuccinimide-dimercaptoethane cobromination of alkenes: synthesis of β,β′-dibromodithioethers

Alkenes react in diethyl ether with N-bromosuccinimide (NBS) and dimercaptoethane to afford the corresponding β,β′-dibromodithioethers. Bromine and dimercaptoethane are added to the aliphatic terminal olefins in an anti-Markovnikov fashion.     

Hydroboration d'aziridudines èthylèniques synthése d'aza-1 bicyclo[n, 1, 0]alcanes

Hydroboration of aziridines having a β or γ-double bond 3b, 3c, 4b, 7c and 8 yields after oxidation, the expected hydroxy aziridines 11b, 11c, 12b, 13 and 14, which were cyclized by reaction with PPh₃/Br₂ to give 1-aza bicyclo[n, 1, 0]alkanes 23b, 24b, 25c, 26 and 27. The hydroboration of 2-vinyl aziridines 3a, 4a and 7a give _Z-allylic amines 16aZ, 17aZ and 18Z. The use of 9-BBN or of 2-vinyl substituted aziridines provides the β-hydroxy aziridines 19, 20 and 21.     

Synthesis of α-Cyano-β-fluoro-α-hydroxyesters

The ring opening fluorination of glycidic gem-cyanoesters was achieved by action of pyridine polyhydrofluoride at 25°C in dichloromethane. The regioselective nucleophilic substitution reaction allows the synthesis of a new class of fluorohydrins with OH, CN and CO₂R on the same carbon atom.     

Synthesis of 2-Fluoro- Acids,Esters, and Amides From Ã-Dicyanoepoxides

The opening of Ã-dicyanoepoxides by pyridine polyhdrofluoride yields polymerisable 2-fluorocyanoformyls which may be kept intact when diluated in dichloromethane or ether. These intermediates react with nuclecophiles such as water, methanol or amines to give respectivly 2-fluoroacids, esters or amides.