Synthesis of highly substituted ureas and thioureas through 1,3-diaza-Claisen rearrangements
作者:Amy M. Bowser、José S. Madalengoitia
DOI:10.1016/j.tetlet.2005.02.132
日期:2005.4
cycloaddition sequence instead of a 1,3-diaza-Claisenrearrangement. Competition experiments between isocyanates and isothiocyanates with limiting azanorbornene indicate that isothiocyanates react faster to give the rearrangement product. Since isocyanates are shown to be more electrophilic, these data are consistent with a fast addition step and a rate-determining rearrangement step.
A 1,3-Diaza-Claisen Rearrangement that Affords Guanidines
作者:Amy M. Bowser、José S. Madalengoitia
DOI:10.1021/ol048575e
日期:2004.9.1
[reaction: see text] N-Alkyl-N'-tosylthioureas activated by EDCI react with azanorbonenes at room temperature through a 1,3-diaza-Claisenrearrangement, affording highly substituted, bicyclic guanidines in moderate to good yields.