Enediynes Subject

A general synthetic route to p-lactam-fused enediynes (Scheme 2.321) has been successfully developed (848). When nitrone (771) was subjected to Kin-ugasa reaction conditions, two p-lactam containing products were obtained the elimination product (772) and the trans fused compound (773). 

Nitrogen-containing 15-membered trialkyne macrocycles, such as l,6,ll-frw(aiylsulfonyl)-l,6,ll-triazacyclopentadeca-3,8,13-triynes and enediynes as 1,6,11-frw(arylsulfonyl)-1,6,11-triazacyclopentadeca-3-ene-8,13-diynes have been prepared and subjected to a [2+2+2]-cyclotrimerization process catalyzed by transition metal complexes, e.g., RhCl(CO)(PPh3)2 <05JOC2033>. The reaction of pemosylated diethylenetriamine and 2-substituted propan-1,3-... 

A third approach to the enediyne core of calicheamicin was reported by Magnus et al. (Scheme 7-46) [186, 200-206]. Cleverly exploiting some interesting organocobalt chemistry, they prepared the acetylenic cobalt complex 201 [201] and subjected it to a Nicholas-type reac-... 

Peptide derivatives were used by Anseth in the construction of hydrogel networks. For example, the peplidyl enediyne 43 was used to cross-Unk with a PEO-derived tetraazide 44 to produce peptide hydrogels 45 (Scheme 13) [54]. The CuAAC-inert alkene functionahties were subsequently subjected to the second functionalization... 

Based partly on the success of benzofused enediynes such as 28, 30, 31, and 34, Wiest prepared highly strained enediynes 36 and 37 and subjected them to conditions suitable for photochemical Bergman cyclization. These molecules proved stable to prolonged high-intensity irradiation. Based on calculations, it was suggested that the unexpected photochemical (and thermal) stability of 36 and 37 is the result of diyl intermediates that are unusually high in energy. 

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