Nitrosopurines En Route to Potently Cytotoxic Asmarines
作者:Kanny K. Wan、Kotaro Iwasaki、Jeffrey C. Umotoy、Dennis W. Wolan、Ryan A. Shenvi
DOI:10.1002/anie.201411493
日期:2015.2.16
A nitrosopurine ene reaction easily assembles the asmarine pharmacophore and transmits remote stereochemistry to the diazepine‐purine hetereocycle. This reaction generates potent cytotoxins which exceed the potency of asmarine A (1.2 μM IC50) and supersede the metabolites as useful leads for biological discovery.
Full details of a stereodivergent hydroboration of allenes are reported. While hydroboration of an allene with 9‐BBN provided a thermodynamically stable (E)‐allylic alcohol after oxidative work‐up, the reaction of an identical allene with HB(Sia)2 (disiamylborane) formed a (Z)‐allylic alcohol as the kinetic product. The developed conditions allowed for the synthesis of trisubstituted olefins in a highly