ChemInform Abstract: ADDITION REACTIONS OF DITHIO ACIDS TO ALKENES. III. RADICAL ADDITION‐ SYNTHESIS AND CHARACTERIZATION OF 2‐ALKYL‐4‐ARYL‐1,3‐DITHIOLANES

Abstract

Die Dithiosäuren (I) reagieren mit Alkenen, wie z.B. (II), in Gegenwart von 2,2.′‐Azo‐bis‐isobuttersäurenitril (AIBN) zu den Dithio1anen(III) (Bildungsmechanismus, NMR‐Spektren).

Study on controlled free-radical polymerization in the presence of dithiobenzoic acid (DTBA)

“…Based on the results obtained, we propose the propagation mechanism as shown in Scheme . DTBA can react with the double bond to form a dithioester (see reaction 1),18–21 which acts as an efficient reversible addition‐fragmentation chain transfer agent. Addition of a propagating radical P n · on dithioester 1 (S = C(Ph)SR) gives an adduct radical 2 which can fragment to form a polymer chain with dithioester group 3 (S = C(Z)SP n ) and a new radical R·.…”

Reaction of Cyclic Tetrathiophosphates with Carboxylic Acids as a Means to Generate Dithioesters and Control Radical Polymerization By RAFT

“…Depending on the electron density of the alkene, the addition can either result in a Michael‐type reaction (path B) or follow a Markownikoff‐type mechanism (path A) 12. 13 Therefore, it is likely that the reaction between PhCOOH and P 4 S 10 first generated DTBA, which subsequently added to styrene to give phenylethyl dithiobenzoate (path A in Scheme ). Such a dithioester, formed in situ, then acted as a chain‐transfer agent (CTA) and controlled the RAFT polymerization of styrene.…”

Reaction of Cyclic Tetrathiophosphates with Carboxylic Acids as a Means to Generate Dithioesters and Control Radical Polymerization By RAFT

“…Depending on the electron density of the alkene, the addition can either result in a Michael‐type reaction (path B) or follow a Markownikoff‐type mechanism (path A) 12. 13 Therefore, it is likely that the reaction between PhCOOH and P 4 S 10 first generated DTBA, which subsequently added to styrene to give phenylethyl dithiobenzoate (path A in Scheme 2). Such a dithioester, formed in situ, then acted as a chain‐transfer agent (CTA) and controlled the RAFT polymerization of styrene.…”