Regioselective terminal aziridine

Synthetic strategy Regioselective terminal aziridine opening - aminoacetylative cyclization cascades... 

The lithiation of /ra .s-A-alkyl-2,3-diphenylaziridines such as 51 was reported to be completely a-regioselective while the stereochemical course of the lithiation-trapping sequence was found to be solvent dependent <07OL1263>. Retention of configuration was observed in hexane, ether, or toluene, while coordinating solvents such as THF or toluene/crown ether produced inversion. Related isomerization and dimerization reactions of a-lithiated terminal aziridines were also reported <07JOC10009>. 

The reaction of thiophene with the styrene-derived aziridine 44 with I11CI5 catalysis involves attack mainly at the more hindered and benzylic carbon, although ca. 10% of product formation derives from terminal attack (Scheme 33) <2002TL1565>. Similarly, In(OTf)3 can be used to promote the reaction of 44 with reactive benzenes, with the same regioselectivity <2001TL8067>. 

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