CHEM164 Lecture Notes - Lecture 11: Sn2 Reaction, Sulfoxide, Concerted Reaction

• School: University of Alberta
• Department: Chemistry
• Course: CHEM164
• Professor: John Vederas

Document Summary

Substitution reactions 2 types: sn1 and sn2. 2 = bimolecular reaction (rate of reaction depends on 2 reagents) stereospecific reaction inversion of configuration. Polar aprotic solvents e. g; dimethyl formamide(dmf), dimethyl sulfoxide rate depends on two reagent concentration: [nu] and [sm] favored for primary 1 & 2 carbons, never 3 centres (dmso), acetonitrile. I > br > cl >> f never; oh , or ,nr. The order of halide leaving group ability is due to solvation and size. Rate depends on 1 concentration: [sm] stepwise (not concerted) One reason is that the oh- is not a good leaving group. Or and oh work if strong acid is present; the hor and hoh are the leaving groups. Sn1 and sn2 can compete with e1 and e2 (alkenes are formed) Alkenes and alkynes term olefin comes from: oleum facere. H ethylene (common name) ethene (systematic name) replace ane of corresponding alkane name with ene