Krow Grant R, Gandla Deepa, Guo Weiwei, Centafont Ryan A, Lin Guoliang, DeBrosse Charles, Sonnet Philip E, Ross Charles W, Ramjit Harri G, Carroll Patrick J, Cannon Kevin C
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA.
J Org Chem. 2008 Mar 21;73(6):2114-21. doi: 10.1021/jo702153q. Epub 2008 Feb 22.
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.
已发现将碘鎓-X试剂添加到N-烷氧羰基-2-氮杂双环[2.2.1]庚-5-烯和同系的2-氮杂双环[2.2.2]辛-5-烯中，与溴鎓-X试剂添加的结果相似。这些卤鎓离子试剂中的任何一种与氮杂双环[2.2.1]庚-5-烯反应时，仅观察到重排产物。对于氮杂双环[2.2.2]辛-5-烯，在添加IOH或BrOH时氮的参与取决于N-烷氧羰基基团。使用较大的N-Boc、N-Cbz或N-Troc保护基团时，通过对顺式卤鎓离子的C(5)进行亲核进攻，形成未重排的5-反式羟基-6-顺式-I(或Br)-二氮杂双环[2.2.2]辛烷。通过X射线分析重新确定了N-甲基-8-反式溴-4-反式羟基-2-氮杂双环[3.2.1]辛烷的结构。
