24892-78-2Relevant articles and documents
Friedel-Crafts Alkylation of Aromatics with exo-2-Chloro- and 7-Chloronorbornane
Olah, George A.,Lee, Chang Soo,Prakash, G. K. Surya
, p. 2590 - 2593 (2007/10/02)
exo-2-Chloro- and 7-chloronorbornane in the presence of tin(IV) chloride or aluminum chloride react with benzene and substituted benzenes to give the corresponding norbornylated products.Mechanistic aspects of the reactions proceeding through carbocationic intermediates are discussed.
Betylates. 2. The formation and high reactivity of alkylbetylates
King, James Frederick,Lee, Teresa Mee-Ling
, p. 362 - 372 (2007/10/02)
Unhindered primary alkyl N,N-dimethylsulfamates (1) react with methyl fluorosulfate to give the corresponding alkyl fluorosulfates (3) and the betaine, Me3N(1+)SO3(1-) (4), evidently by way of the intermediate alkylbetylate fluorosulfate (2); with certain other alkyl esters (1) products of substitution, elimination, and rearrangement are formed.The reaction not only provides a potentially useful route to simple alkyl fluorosulfates, but serves to demonstrate the powerful nucleofugality of the betylate group.To obtain a method for predicting the reactivity of betylates, we have compared substituent parameters with rate constants in four series of nucleophilic displacement involving esters of the general structure ROSO2Z; correlation (of log k) with ?* is mediocre but a new parameter, ?15* with a "15percent resonance" contribution as defined by Swain and Lupton, gives good to excellent agreement in the four reaction series.Evidence is presented for formation of the 7-norbornyl cation via the betylate from 7-norbornyl N,N-dimethylsulfamate and methyl fluorosulfate.Comparison with what is known of the reactivities of 7-norbornyl p-toluenesulfonate and trifluoromethanesulfonate esters serves to confirm that betylates are among the most nucleofugal functions of which a derivative has been fully characterized.
