Mechanistic study of 7-endo selective radical cyclization of the aryl radical
摘要:
Mechanistic studies on the novel 7-endo selective radical cyclization were carried out. The reaction afforded three products, 7-endo product, 6-exo product, and reduced product. The distribution of these products was estimated by GC analyses. The 7-endo/6-exo selectivity was almost constant against variation in the concentration of Bu3SnH, while the reduction/cyclization ratio was sensitive to the concentration of Bu3SnH. The reduction/cyclization ratio was mainly affected by the rotational isomeric ratio of the cyclization precursor. Kinetic analyses indicated that the cyclization process should be irreversible, and the rate constant of 7-endo/6-exo radical cyclization was estimated to be about 3.3 x 10(8) s (1) at 80 degrees C. (C) 2009 Elsevier Ltd. All rights reserved.
An efficient preparation of N-alkyl-2-benzazepine derivatives and investigation of their biological activity
摘要:
N-Alkyl-2-benzazepine derivatives are readily prepared through N-alkylation of secondary 2-benzazepines that are constructed via 7-endo selective cyclization of radical cyclization of N-boc-N-(2-bromo5-methoxyphenylmethyl) methacrylamides. The structure and activity relationship of these derivatives are examined. (C) 2009 Elsevier Ltd. All rights reserved.
N-Alkyl-2-benzazepine derivatives are readily prepared through N-alkylation of secondary 2-benzazepines that are constructed via 7-endo selective cyclization of radical cyclization of N-boc-N-(2-bromo5-methoxyphenylmethyl) methacrylamides. The structure and activity relationship of these derivatives are examined. (C) 2009 Elsevier Ltd. All rights reserved.
Mechanistic study of 7-endo selective radical cyclization of the aryl radical
Mechanistic studies on the novel 7-endo selective radical cyclization were carried out. The reaction afforded three products, 7-endo product, 6-exo product, and reduced product. The distribution of these products was estimated by GC analyses. The 7-endo/6-exo selectivity was almost constant against variation in the concentration of Bu3SnH, while the reduction/cyclization ratio was sensitive to the concentration of Bu3SnH. The reduction/cyclization ratio was mainly affected by the rotational isomeric ratio of the cyclization precursor. Kinetic analyses indicated that the cyclization process should be irreversible, and the rate constant of 7-endo/6-exo radical cyclization was estimated to be about 3.3 x 10(8) s (1) at 80 degrees C. (C) 2009 Elsevier Ltd. All rights reserved.