Du, W and Curran, DP (2003) Cascade 4+1 radical annulations of 2,6-disubstituted phenyl isonitriles with N-propargyl-6-iodopyridones: Scope, mechanism and regioselective synthesis of 7,9-disubstituted camptothecin analogs. Synlett (9 SPEC). 1299 - 1302. ISSN 0936-5214