Ferrocene and Silicon-Containing Oxathiacrown Macrocycles and Linear Oligo-Oxathioethers Obtained via Thiol–Ene Chemistry of a Redox-Active Bifunctional Vinyldisiloxane

Abstract

The application of 1,3-divinyl-1,3-dimethyl-1,3-diferrocenyldisiloxane [(CH2═CH)FcMeSi]2O (1) as an efficient electroactive vinylsilane precursor for thiol–ene radical reactions is described. In order to determine if steric or electronic limitations due to the redox-active metallocene moiety might affect the bis(hydrothiolation) of the bifunctional vinylsilane, a model reaction was initially performed between 1 and 2-mercaptoethanol, resulting in the formation of the newly sulfur-containing carbosiloxane 2 in excellent yield. The bis(thiol–ene) reaction of 1 was successfully extended to 2,2′-(ethylenedioxy)diethanethiol, affording a series of novel precisely defined, redox-active oxathiacrown macrocycles (3 and 4n) and sulfur-bearing linear oligo-carbosiloxanes (5n and 6n) with a backbone in which the −S(CH2)2–O(CH2)2O–(CH2)2S– chain and the −Si–O–Si– bond, bearing pendant ferrocenes, are alternately linked by ethylene bridges. These reactions have been initiated either thermally (in toluene solution with...