New Soluble Polysiloxane Polymers containing a Pendent Terdentate Aryliamine Ligand substituent Holding a Highly Catalytical Active Organometallic Nickel(II) Centre

Abstract

A new type of grafted polysiloxane polymer is described in which an aryldiamine substituent, [CsH3(CHzNMe2)2-2,61-, provides a pendant terdentate ligand environment for a catalytically active (0rgano)nickel center. The novel strategy employed involves initial grafting of the aryl bromide 5-amino-2-bromo-1,3-bis[(dimethylamino)methyllbenzeinnet o the side chain of poly((2-(chlorocarbonyl)ethyl)methylsiloxane~f ollowed by nickel incorporation through an oxidative addition reaction with [Nio(COD)21 (COD = cycloocta-1,5-diene). Soluble polymers with different amounts of nickel incorporation have been prepared and characterized by NMR, FT-IR, and W/vis spectroscopy as well as by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). These polymeric materials having an immobilized organonickel(I1) center show good catalytic activity in the Kharasch addition reaction of polyhalogenated alkanes to alkenes that is of the same order of magnitude as for the comparable model organonickel(I1) complex [Ni{ CsH2(CH2NMe2)2-2,6-N(H)C(O)- Me-4)BrI.