Neighboring group participation in the additions of iodonium and bromonium ions to N-alkoxycarbonyl-2-azabicyclo[2.2.n]alk-5-enes (n = 1,2).
Additions of iodonium-X reagents to N-alkoxycarbonyl-2-azabicyclo[2.2.1]hept-5-enes and the homologous 2-azabicyclo[2.2.2]oct-5-enes have been found to mirror the outcomes of additions of bromonium-X reagents. Only rearranged products were observed for reactions of either of these halonium ion reagents with the azabicylo[2.2.1]hept-5-enes. For the azabicyclo[2.2.2]oct-5-enes, nitrogen participation in addition of IOH or BrOH was dependent on the N-alkoxycarbonyl group. With larger N-Boc, N-Cbz, or N-Troc protecting groups, unrearranged 5-anti-hydroxy-6-syn-I(or Br)-2-azabicyclo[2.2.2]octanes were formed by nucleophilic attack at C(5) on syn-halonium ions. The structure of N-methyl-8-anti-bromo-4-anti-hydroxy-2-azabicyclo[3.2.1]octane has been reassigned by X-ray analysis.
Krow
Grant R
GR
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA. grantkrow@aol.com
Gandla
Deepa
D
Guo
Weiwei
W
Centafont
Ryan A
RA
Lin
Guoliang
G
DeBrosse
Charles
C
Sonnet
Philip E
PE
Ross
Charles W
CW
Ramjit
Harri G
HG
Carroll
Patrick J
PJ
Cannon
Kevin C
KC
D053961:Azabicyclo Compounds / Q000737:chemistry*; D017605:Bromine Compounds / Q000737:chemistry; D003516:Cycloparaffins / Q000737:chemistry*; D017613:Iodine Compounds / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009861:Onium Compounds / Q000737:chemistry*
D053961:Azabicyclo Compounds; D017605:Bromine Compounds; D003516:Cycloparaffins; D017613:Iodine Compounds; D009861:Onium Compounds