Total Synthesis of Dictyodendrin A and B

Abstract

In‐do‐line of fire: A highly efficient total synthesis of the title compounds features a novel benzyne‐mediated one‐pot indoline formation/cross‐coupling sequence for the construction of a highly substituted key indoline intermediate. The peripheral substituents were then introduced onto the intermediate in a modular fashion to complete the total syntheses of dictyodendrin A and B.

An Obtuse‐angled Corner Unit for Fluctuating Carbon Nanohoops

“…We first prepared the corner unit in the form of bromophenylated 9,10-epoxyanthracene. Benzyne generated from phenyl trifluoromethanesulfonate and magnesium amide [Mg(TMP) 2 ·2 LiCl] [16] was adopted fort he Diels-Alder reaction with bromophenylated isobenzofuran 1 [17] to afford the corner unit 2 in ag ood yield (Scheme 1). [18,19] The corner unit 2 was then subjected to the Ni-mediated, Yamamoto-type macrocyclization reaction.…”

Recent Accomplishments in the Total Synthesis of Natural Products Through C–H Functionalization Strategies

“…Between 2005 and 2006, Fuerstner and coworkers reported the first total syntheses of dictyodendrins B, C, and E [48,49] followed by Tokuyama and coworkers in 2010 with the first total synthesis of dictyodendrin A and the syntheses of the B-E analogs [50,51].…”

“…The end game to obtain over 1 g of dictyodendrin B (5b) followed the previously described four steps of deprotection and sulfonylation [49,51]. To sum up, a modular synthesis of dictyodendrin B (5b) was completed and tailored using a wide range of C-H functionalization reactions.…”

Recent Applications and Developments of Organic Azides in Total Synthesis of Natural Products

“…A-E 51-55 possessing inhibitory activity against telomerase, which were isolated from Japanese marine sponge Dictyodendrilla verongiformis (Scheme 11) [45,46]. Carbazole skeletons in dictyodendrins were constructed from biaryl azides 43-45, which were prepared with azidoiodobenzene 42 through Suzuki-Miyaura coupling [47].…”