Reactions at low temperature of AlEt3 or ethyl‐aluminum‐chlorides with Me3CCl and addition of ethylene to cationic species

Reactions between Et3–xAlClx (where x = 0, 1, 2, 3) and Me3CCl, carried out in CH2Cl2, CH3Cl or n‐pentane at −78°C, have been investigated by VPC‐MS analysis of the resulting products. The use of CD2Cl2 and (CD3)3CCl made it possible to confirm the suggested reactions. Under mild conditions and in the presence of ethylene the system EtAlCl2 + Me3CCl yields branched, saturated C6, C8, and C10 hydrocarbons. Conductimetric and NMR observations during the reactions have confirmed the VPC–MS results, which could be interpreted according to an overall cationic mechanism involving the following reactions: Abstraction of a β‐hydrogen atom from an ethyl group linked to Al and simultaneous formation of ethylene; repeated addition of ethylene to cationic species; termination by hydride transfer; termination by chloride ion abstraction by carbonium ions .