H3C
N NH The discovery of a new reactive intermediate leads to H O the development of new reactions! ? O
R2
R1
R
N
N H
X
O
Bn
R
O
R2
Et3N (2.0 equiv)
R1 O
N
O
TFE or HFIP 0 °C to 25 °C
O
Bn
Generation and Reactivity of Aza-Oxyallyl Cationic Intermediates: Aza-[4 + 3] Cycloaddition Reactions for Heterocycle Synthesis Christopher S. Jeffrey, Korry L. Barnes, John A. Eickhoff and ,Christopher R. Carson J. Am. Chem. Soc. 2011, 133, 7688-7691
O O N
R
O O
O
O
N
R
Novel reactivity produces novel heterocyclic products from simple starting materials
Bn
N H
N
TFP-Na (2.0 eq)
OR2
Bn
N A
TFP:diene (1:2)
Cl
R = Bn, Et, or Me
N
OR
65-98 %
Christopher S. Jeffrey, Devendar Anumandla, Christopher R. Carson Org. Lett. ASAP
R1
R2 O
Br
N H A
O
LiClO4, Et3N, Et2O or
R1 R2
O A N
O
Et3N, TFE, rt
50-85 % ~ 3:1 endo:exo