Should dithiophosphinate esters function as RAFT agents?
[graph: see text] High-level ab initio calculations indicate that *CH3 addition to the sulfur center of S=P(Z)(Z')SCH3 (Z,Z' = CH3, CN, OCH3, Ph) is considerably less exothermic than addition to the corresponding RAFT agents, S=C(Z)SCH3. This suggests that dithiophosphinate esters may have only limited use in controlling free-radical polymerization, but should make excellent radical chain carriers in organic synthesis. The results cast doubt on the notion that phosphoranyl radicals are more "intrinsically" stabilized than carbon-centered radicals.
Hodgson
Jennifer L
JL
ARC Centre of Excellence in Free Radical Chemistry and Biotechnology, Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.
Green
Katy A
KA
Coote
Michelle L
ML