Preparation and evaluation of<i>N</i>‐sulfinyl dienophiles for asymmetric hetero‐diels‐alder reactions
作者:Molla Mellese Endeshaw、Lars K. Hansen、Odd R. Gautun
DOI:10.1002/jhet.5570450115
日期:2008.1
A series of N-sulfinyl dienophiles 1c-i has been screened in asymmetric hetero-Diels-Alder reactions using chiral bis(oxazoline)copper(II) and -zinc(II) triflates. The survey pointed out N-sulfine 1c (R P(O)(OPh)2) as the most promising N-sulfine regarding yield and stereoselectivity (up to 97% ee). The relative configurations, and in one case the absolute configuration, of the HDA adducts were established
1,2,3,5-Tetrazines and 1,2,3-triazaspiro[4.4]nonanes: remarkable products from 1,3-dipolar cycloadditions of N-sulphinylamines with substituted triazolium imides
作者:Richard N. Butler、D. Cunningham、Patrick McArdle、Gerard A. O'Halloran
DOI:10.1039/c39880000232
日期:——
Cycloadditions of aryl-N-sulphinylamines with substitutedtriazoliumimides gave new 8π-2,4,5,6-tetrasubstituted-1,2,3,5-tetrazines, the X-ray crystal structure 〈′Uone of which is reported; strained tricyclic tetra-aza tetracyclo[4.3.1.01,6]decenes are suspected as intermediates and attempts to intercept them led to new substituted1,2,3-triazaspiro[4.4]nonanes, the X-ray crystal structure of one of