Reactions of the tert-butylthiyl radical with organometallic compounds and alkenes

Absolute rate constants for the reactions of the tert-butylthiyl radical with a variety of substrates were measured by using a combination of laser flash photolysis techniques and product studies. Reactions with organometallic substrates such as boranes, phosphines, and phosphites were extremely rapid with rate constants in the range 10{sup 8}-10{sup 9} M{sup {minus}1} s{sup {minus}1}. By contrast, addition to a simple olefin, oct-1-ene, was ca. 100 times less rapid. However, 1,1-diphenyl- and 1,1-dicyclopropylethylene were remarkably efficient traps for tert-butylthiyl and scavenged the radical with rate constants of 9.9 {times} 10{sup 8} and 2.4 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}, respectively.