Sequenced reactions with samarium(II) iodide. Intermolecular ketyl-olefin coupling/intramolecular nucleophilic acyl substitution for the preparation of six-, seven-, and eight-membered carbocycles
作者:Gary A Molander、Masakazu Sono
DOI:10.1016/s0040-4020(98)00584-5
日期:1998.8
A samarium(II) iodide-promoted sequence consisting of an intermolecular ketyl-olefin coupling followed by an intramolecular nucleophilic acyl substitution is described. This process leads to functionalized six- to eight-membered monocyclic and bicyclic ring systems in moderate to good yields.
Hanessian, Stephen; Dhanoa, Daljit S.; Beaulieu, Pierre L., Canadian Journal of Chemistry, 1987, vol. 65, p. 1859 - 1866
作者:Hanessian, Stephen、Dhanoa, Daljit S.、Beaulieu, Pierre L.
DOI:——
日期:——
Sequenced Reactions with Samarium(II) Iodide. A Complementary Annulation Process Providing Access to Seven-, Eight-, and Nine-Membered Carbocycles
作者:Gary A. Molander、Fouzia Machrouhi
DOI:10.1021/jo990216n
日期:1999.5.1
Samarium(II) iodide promotes an efficient one-pot annulation reaction between omega-iodo esters and 2-(omega-chloroalkyl)cycloalkanones. An initial intermolecular carbonyl addition reaction between the iodo ester and the ketone generates a lactone intermediate. The lactone undergoes a subsequent nucleophilic acyl substitution reaction with an organosamarium derived from the chloride. Nickel(II) iodide is an efficient catalyst for the first step of the process, and light is utilized to promote the second step. Seven-, eight-, and nine-membered rings can be accessed by this sequential dianionic process. This annulative approach to carbocycles is complementary to previously reported procedures.
Asymmetric induction in the nucleophilic cyclopropane ring cleavage reaction with vitamin B12s