Diels-Alder reactions of 5-amino- 1,3-cyclopentadiene have not been reported, and other stereoselective, high-yield routes to substituted bicyclo[2.2.1]hept-2-en-7-syn-amines are limited. This paper reports use of (n5-C5H5)Fe-(CO)2(n1-C5H5) (1) as a synthetic equivalent of 5-amino-1,3-cyclopentadiene in cycloaddition reactions. The previously reported cycloadducts of 1 and alkenes were treated with ammonium cerium(IV) nitrate, bromine, or chlorine in acetonitrile containing sodium azide to give the corresponding acyl azides in which the CON3 group replaced the (n5-C5H5)Fe(CO)2 group with retention of stereochemistry in good yield. Thermal Curtius rearrangement of these acyl azides proceeded stereospecifically in excellent yield. This regioselective and stereoselective sequence provides a useful route to substituted 7-syn-amino-2-norbornenes.
ASJC Scopus subject areas
- Organic Chemistry