Ruthenium-Catalyzed Cycloisomerization−6π-Cyclization: A Novel Route to Pyridines
摘要:
Herein we report a method for the synthesis of substituted pyridines. The unsaturated ketones and aldehydes derived from the cycloisomerization of primary and secondary propargyl diynols in the presence of [CpRu(CH3CN)(3)]PF6 (1) are converted to 1-azatrienes which in turn undergo a subsequent electrocyclization-dehydration to provide pyridines with excellent regiocontrol.
An Unusual Ruthenium-Catalyzed Cycloisomerization of Alkynes and Propargyl Alcohols
作者:Barry M. Trost、Michael T. Rudd
DOI:10.1021/ja012672a
日期:2002.4.1
CpRu(NCCH3)3+PF6- catalyzes the cycloisomerization of diyne-ols to alpha,beta,gamma,delta-unsaturated aldehydes and ketones in good-to-excellent yields. 1-Hydroxy-2,7-diynes and 1-hydroxy-2,8-diynes can be utilized to form highly functionalized five- and six-membered rings, respectively. Tertiary as well as secondary propargyl alcohols are cycloisomerized to a single isomeric product. A wide variety