Synthesis, Structure, and Reactivity of Enediyne Macrocycles

Abstract
The reaction of bis-propargyl bromide enediyne 4 with weakly basic nucleophiles allows the facile synthesis of acyclic and macrocyclic enediynes. Depending on the bis-nucleophile employed, 12- to 16-membered enediyne macrocycles were obtained. The thermal stability of the new cyclic enediynes was investigated by differential scanning calorimetry. Upon coordination of the macrocycle 5c with Hg(O2CCF3)2, a drop of the enediyne cyclization temperature of nearly 100 K was observed.