Construction of the oxaphenalene skeletons of mansonone F derivatives through C–H bond functionalization and their evaluation for anti-proliferative activities

Abstract

Novel mansonone F derivatives were conveniently synthesized via a key step of Ru(II)-catalyzed C-H functionalization to rapidly construct oxaphenalene skeletons. This synthetic procedure is sufficiently robust and flexible to offer both the generation of diverse mansonone F analogs and the scale-up synthesis of selected compounds. The structural formulas of all products were confirmed and characterized using spectral data. Most of the derivatives exhibited significant cytotoxicity against four tested human tumor cell lines in vitro.

Synthesis of Functionalized Cyclobutane‐Fused Naphthalene Derivatives via Cascade Reactions of Allenynes with tert‐Butyl Nitrite

“…Another unexpected product, 1-nitro-1-phenyl-1,2-dihydrocyclobuta[a]naphthalene-3,4-dione (4 a), was also isolated in a yield of 10%. [13,14] In addition, they are also prevalent in naturally occurring and man-made compounds with potent biological activities. This is mainly due to the fact that compounds containing either the cyclobutanol moiety as embedded in 3 a [11,12] or the naphthalene-1,2dione unit as present in 4 a are useful precursors toward various kinds of fine chemicals.…”

“…Although A was not obtained, the unprecedented formation of 3 a and 4 a from the reaction of 1 a with 2 is no less interesting. [11][12][13][14] To improve its efficiency and selectivity, several parameters possibly affecting this reaction were screened. [13,14] In addition, they are also prevalent in naturally occurring and man-made compounds with potent biological activities.…”

“…This is mainly due to the fact that compounds containing either the cyclobutanol moiety as embedded in 3 a [11,12] or the naphthalene-1,2dione unit as present in 4 a are useful precursors toward various kinds of fine chemicals. Further studies in varying the loadings of TEMPO and TBN did not give more positive results (entries [12][13][14][15]. A literature search revealed that reliable and sustainable methods for their synthesis are very limited.…”

“…A literature search revealed that reliable and sustainable methods for their synthesis are very limited. [11][12][13][14] To improve its efficiency and selectivity, several parameters possibly affecting this reaction were screened. Toluene, dioxane, DCE or THF was tried to replace CH 3 CN as the reaction medium (entries 2-5).…”

“…In the presence of TEM-PO, 4 a was obtained in 66% yield while 3 a was formed only in a trace amount (entry 11). Further studies in varying the loadings of TEMPO and TBN did not give more positive results (entries [12][13][14][15].…”