Highly regioselective ring opening of 2,3-dimethyloxirane, 2-epoxyphenylether and allyl(2-epoxymethyl) ether are observed through reactions with poor nucleophiles such as indole, borane, O-trimethylsilylhydroxylamine, p-nitroaniline and sterically hindered tert-butylamine in the presence of 5.0 M lithium perchlorate-Et 2 O solution. These reactions are fast, convenient, with rather high yields and are carried out at ambient temperatures.Key words: lithium perchlorate, epoxide, b-amino alcohols Oxiranes (epoxides) are widely distributed in nature and are of industrial and biochemical interest. In addition, they are becoming a powerful tool in the field of synthetic organic chemistry. 1 Epoxides are efficiently converted into functionalized alcohols by employing nucleophilic ringopening reactions. However, this reaction, which is usually carried out with a large excess of nucleophiles at elevated temperature with long reaction times and drastic conditions, often fails when poor nucleophiles and/or sterically bulky nucleophiles or epoxides are used. 2 Therefore, there is a significant current interest in the ring opening of epoxides.b-Amino alcohols constitute an important class of wellknown organic compounds that have importance in natural products, medicinal chemistry and other chemical fields. 3 The most practical and widely used method for preparing these compounds is the direct aminolysis of epoxides with an excess of amines or their synthetic equivalents at elevated temperatures. 4 Due to the elevated temperature, these reactions often fail when poorly nucleophilic or sterically bulky amines and in some case low boiling points amines are concerned. These are some significant limitations on the general utility of epoxide aminolysis. 5 To obviate these problems, several useful modifications activator/promoters have been reported: COCl 2 , 6 fluoro-alcohols as reaction media 7 (benzylic and aliphatic amines do not react under these conditions), Ti(O-i-Pr) 4 , 8 SmI 2 and SmCl 3 , 9 metal triflates, 10 metal amides, 11 Mg, Li, Pb, Sn, Si (an important drawback of these methods is that epoxides bearing a-hydrogens, frequently undergo rearrangement to produce allyl alcohols and primary amines show no regioselectivity). Good regioselectivity of ring opening by nucleophiles has been observed with LiClO 4 . 12 However, with this catalyst, deactivated aromatic amines and some sterically hindered amines fail to open up epoxides or require high temperature or pressure. Although a wide choice of promoters is available many are associated with one or other drawback. Hence, there is a need for new versatile methods.In the course of our investigations toward the development of new reactions promoted by lithium perchlorate in Et 2 O (LPDE) solution, we have found that 5.0 M LPDE solutions promote the addition of deactivated p-nitroaniline and secondary amines to epoxides under mild experimental conditions (r.t., 30 min). 13 The reaction was highly regioselective as 3 was the only detectable product. The results are summarize...
