same time, uncaging releases a strongly fluorescent coproduct that can be used as a reporter for quantitative substrate delivery. The quantum yield of double bond photoisomerization leading to uncaging after one-photon absorption mostly lies in the 10% range. Taking advantage of the favorable photophysical properties of the uncaging coproduct, we use a series of techniques based on fluorescence emission
Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-<i>tert</i>-butyl Peroxide (DTBP) through a C(sp<sup>2</sup>)-H Functionalization Process
have developed two new couplingreactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp2)–H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These couplingreactions will enrich current coumarin
Copper(I)-Catalyzed 3-Position Methylation of Coumarins by Using Di-<i>tert</i>-butyl Peroxide as the Methylation Reagents
作者:Huan Zhuang、Runsheng Zeng、Jianping Zou
DOI:10.1002/cjoc.201500836
日期:2016.4
The copper‐catalyzed methylation of coumarin by using di‐tert‐butyl peroxide (DTBP) has been described. The reaction provides direct access to a wide range of 3‐methylcoumarins in moderate to good yields. In this procedure, it is noteworthy that DTBP was employed not only as the oxidant, but also as the methyl source.