Mild Mn(OAc)<sub>3</sub>-Mediated Aerobic Oxidative Decarboxylative Coupling of Arylboronic Acids and Arylpropiolic Acids: Direct Access to Diaryl 1,2-Diketones
作者:Wen-Xin Lv、Yao-Fu Zeng、Shang-Shi Zhang、Qingjiang Li、Honggen Wang
DOI:10.1021/acs.orglett.5b01265
日期:2015.6.19
A simple and efficient method for the synthesis of diaryl 1,2-diketones has been developed. The reaction represents the first example of diaryl 1,2-diketones that are synthesized directly from arylboronic acids and arylpropiolicacids by a radical pathway in moderate to good yields. This reaction proceeds under mild reaction conditions and with good tolerance of a variety of functional groups. Preliminary
This paper reports the oxidation of functionalized diarylalkynes with DMSO in the presence of the environmentally friendly FeBr3 catalyst. This non-toxic procedure is general and has been applied successfully under microwave irradiation leading rapidly to benzil derivatives in good yields.
A series of benzil derivatives related to combretastatin A-4 (CA-4) have been synthesized by oxidation of diarylalkynes promoted by PdI2 in DMSO. Using this new protocol, 14 benzils were prepared in good to excellent yields and their biological activity has been delineated. Several benzils exhibited excellent antiproliferative activity: for example, 4j and 4k bearing the greatest resemblance to CA-4 and AVE-8062, respectively, were found to inhibit cell growth at the nanomolar level (20-50 nM) on four human tumor cell lines. Flow cytometric analysis indicates that these compounds act as antimitotics and arrest the cell cycle in G(2)/M phase. A cell-based assay indicated that compounds 4j and 4k displayed a similar inhibition of tubulin assembly with an IC50 value similar to CA-4. These results clearly demonstrated that the Z-double bond of CA-4 can be replaced by a 1,2-diketone unit without significant loss of cytotoxicity and inhibition of tubulin assembly potency. (C) 2008 Elsevier Ltd. All rights reserved.