Convenient Synthesis of Highly Functionalized Pyrazolines via Mild, Photoactivated 1,3-Dipolar Cycloaddition
作者:Yizhong Wang、Claudia I. Rivera Vera、Qing Lin
DOI:10.1021/ol7017328
日期:2007.10.1
cycloaddition procedure was successfully developed for the synthesis of polysubstituted pyrazolines. This procedure involved the in situ generation of the reactive nitrile imine dipoles using a hand-held UV lamp at 302 nm, followed by spontaneous cycloaddition with a broad range of 1,3-dipolarophiles with excellent solvent compatibility, functional group tolerance, regioselectivity, and yield.
Lewis Acid Coordinated Nitrile Oxide and Nitrile Imine 1,3-Dipoles.<i>syn</i>-Selective Cycloadditions to 2-(1-Hydroxyalkyl)acrylates
作者:Shuji Kanemasa、Shigeru Kobayashi
DOI:10.1246/bcsj.66.2685
日期:1993.9
chlorides with organometallics or carbohydrazonoyl chlorides with metal alkoxides or amides offers a new generation of Lewis acid-coordinated nitrileoxide and nitrile imine 1,3-dipoles, respectively. These 1,3-dipole/Lewis acid complexes undergo syn-selective cycloaddition reactions to 2-(1-hydroxyalkyl)acrylates through a chelated transition state, while free dipoles show anti-selectivities.
Environmentally Benign Lewis Acid Promoted [2+3] Dipolar Cycloaddition Reactions of Nitrile Imines with Alkenes in Water
作者:Sureshbabu Dadiboyena、Ashton T. Hamme
DOI:10.1002/ejoc.201300840
日期:2013.11
and environmentallybenignLewisacidpromoted 1,3-dipolar cycloadditionreactions of alpha-hydrazonyl chlorides with alkenes in water are reported. These alpha-hydrazonyl chlorides, in the presence of Lewisacids, generate nitrileimines in situ which react with dipolarophiles to furnish the corresponding cycloaddition products. In many cases, the required times for the completion of the Lewis acid