D. A. Evans. M. Calter The Aza-Cope Rearrangement Chem 115 Review The 3-aza-Cope Rearrangement Heimgartner, H In"Iminium Salts in Organic Chemistry". Bohme, H, Viehe, H, Eds. Wiley: New York, 1979; Part 2 pp655-732 First Neutral Case: Hill TL 1967. 1421 The 3-aza-Cope Rearrangement ■ Neutral variant M、入Me250°,Me Practically quantitative", no real 2 y Me 1hr Exothermic as written by -7-10kcal/mole First Cationic Case: Elkik Compt Rend. 1968, 267, 623 ■ Ammonium variant 80 No yields given Even more exothermic than the neutral version has st inium salt tronger p-Bond than imine does 2-aza- Cope Rearrangement OHC. In the simplest case, degenerate. Sterics or con- ing f a particul omer, will drive equilibrium to one side. As with Good way to allylate aldehydes: Opitz Angew. Chem. 1960, 72, 169 H20 a 1-aza-Cope Rearrangement u e incorporating the imine into a strained ring or OHC. R R"\ 32B-0111/2493924AMD. A. Evans, M. Calter The Aza-Cope Rearrangement Chem 115 Review: Heimgartner, H. In "Iminium Salts in Organic Chemistry"; Bohme, H., Viehe, H., Eds.; Wiley: New York, 1979; Part 2, pp 655-732. The 3-aza-Cope Rearrangement: [3,3] Exothermic as written by ~7-10kcal/mole. ■ Ammonium Variant: [3,3] + + Even more exothermic than the neutral version, since enamine lacks resonance and iminium salt has stronger p-Bond than imine does. 1 2 3 1 2 3 ■ Neutral Variant: ■ 2-aza-Cope Rearrangement: 3 2 1 + [3,3] + 1 2 In the simplest case, degenerate. Sterics or con￾jugation, or selective trapping of a particular isomer, will drive equilibrium to one side. As with the 3-aza-Cope, the cationic version goes under much milder conditions. ■ 1-aza-Cope Rearrangement: 3 2 1 3 2 1 [3,3] The 3-aza-Cope rearrangement can be driven in reverse by judicious choice of substrates(i.e., incorporating the imine into a strained ring or by making R an acyl group). The 3-aza-Cope Rearrangement First Neutral Case: Hill TL 1967, 1421. 250oC, 1 hr "Practically quantitative", no real yields given. First Cationic Case: Elkik Compt. Rend. 1968, 267, 623. 80oC, 2-3 hr + + H2O No yields given. Good way to allylate aldehydes: Opitz Angew. Chem. 1960, 72, 169. ∆ + H2O + + + -H2O N N R R N N R R R R N R N R N R N R N Me Me Me N Me Me Me Me N Me Me N Me Me Me Me Me OHC R' Me R OHC Me N R'' H R'' R R' N R'' R'' X R''' N R'' R'' R' R R''' R''' R OHC R''' R' N R'' R R' R'' 32B-01 11/24/93 9:24 AM