Study of the stability of carbocations by chlorosulfonyl isocyanate reaction with ethers

The stability order of various alkyl, allyl, and benzyl carbocations was investigated using the novel technique for comparing the stability of carbocations in solution developed by using a simple CSI reaction with various ethers. The p-methoxycinnamyl carbocation was the most stable in our reaction system and the next stable carbocation was the p-methoxybenzyl carbocation. The stability of the other carbocations decreased with methacryl, t-butyl, cinnamyl, acryl, benzyl, 2° and allyl carbocations in that order.