https://pubs.rsc.org/en/Content/ArticleLanding/2014/CC/C4CC03816A
4-Halogeno-sydnones for fast strain promoted cycloaddition with bicyclo-[6.1.0]-nonyne - Chemical...
New sydnone derivatives have been synthesized and screened for their capacity to undergo fast copper-free cycloaddition reaction with bicyclo-[6.1.0]-nonyne....