Regiochemical preferences in selenoaldehyde cycloadditions
作者:Peter T. Meinke、Grant A. Krafft
DOI:10.1016/s0040-4039(00)95607-7
日期:——
regiochecnical preferences of substituted selenoaldehydes in cycloaddition reactions with electronically biased dienes have been examined. Selenoaldehydes substituted with electron withdrawing groups exhibit “ortho-para” orientation, while selenoaldehydes substituted with donating or conjugating groups exhibit “meta” orientation. Nitrile oxide dipolar cycloadditions of selenoformaldehyde and selenobenzaldehyde
An efficient 1,3-dipolar cycloaddition between aromatic selenoaldehydes and nitrile oxides or nitrile imines: an easy access to selenium-containing five-membered heterocyclic ring system
1,3-Dipolar cycloaddition between aromatic selenoaldehydes, generated by thermal retro Diels–Alder reaction of anthracene cycloadducts, and nitrileoxides or nitrile imines proceeded efficiently to give the corresponding [3+2] cycloadducts as a single isomer in good yields, being 1,4,2-oxaselenazoles or 1,3,4-selenadiazoles, respectively.