Compounds of the general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are herein described, A is a straight or branched (C.sub.2 -C.sub.12)alkyl or a phenyl moiety and B is a moiety of the formula: ##STR2## The compounds are effective in potentiating the activity of chemotherapeutic anti-cancer agents by increasing the sensitivity of multi-drug resistant cells to such chemotherapeutic agents.
Palladium-Catalyzed C–H Alkenylation of Arenes Using Thioethers as Directing Groups
作者:Ming Yu、Yongju Xie、Chunsong Xie、Yuhong Zhang
DOI:10.1021/ol3006997
日期:2012.4.20
Thioethers have been proven to be reliable directinggroups for palladium catalyzed alkenylation of arenes via C–H activation. Mechanistic investigation reveals that the C–H cleavage of arenes is the turnover-limiting step, and an acetate-bridged dinuclear cyclopalladation intermediate is involved. The alkenylated thioethers can be easily removed and transformed into a variety of useful groups.