Meerwein, Hans rearrangement

Carbocations are reactive intermediates in many organic reactions. This idea, first proposed by Julius Stieglitz in 1899 (on the constitution of the salts of imido-ethers and other carbimide derivatives), was further developed by Hans Meerwein in his 1922 study of the Wagner-Meerwein rearrangement Carbocations were also found to be involved in the Sj l reaction and El reaction and in rearrangement reactions such as the Whitmore 1,2 shift. The chemical establishment was reluctant to accept the notion of a carbocation and for a long time the Journal of the American Chemical Society refused articles that mentioned them. 

Wagner, G. J. Russ. Phys. Chem. Soc. 1899, 31, 690. Wagner first observed this rearrangement in 1899 and German ehemist Hans Meerwein unveiled the mechanism in 1914. 

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