Green and Rapid Access to Benzocoumarins<i>via</i>Direct Benzene Construction through Base-Mediated Formal [4+2] Reaction and Air Oxidation
作者:Chengli Mou、Tingshun Zhu、Pengcheng Zheng、Song Yang、Bao-An Song、Yonggui Robin Chi
DOI:10.1002/adsc.201500771
日期:2016.3.3
typically with an intramolecular ester forming reaction to make the lactone ring as the last step. Another major method involves transition metal‐catalyzed coupling or carbon‐hydrogen bond activation reactions starting with pre‐existing aryl frameworks in the substrates. Here we report a new strategy for the green and rapidaccess to benzocoumarins and their derivatives. Our method uses readily available
Oxidant controlled regioselective mono- and di-functionalization reactions of coumarins
作者:Arghya Banerjee、Sourav Kumar Santra、Nilufa Khatun、Wajid Ali、Bhisma K. Patel
DOI:10.1039/c5cc06200d
日期:——
C-3 alkylation of coumarins has been accomplished using cycloalkanes/alkylbenzenes and FeIII/DTBP while C-4 cycloalkylation–C-3 peroxidation has been achieved using AcOH/TBHP.
ANALYTE DETECTION USING NEAR-INFRARED FLUOROPHORES
申请人:Portland State University
公开号:US20160223558A1
公开(公告)日:2016-08-04
Embodiments of compounds for selectively detecting an analyte are disclosed, along with methods and kits for detecting analytes with the compounds. The compounds are bridged viologen conjugates including at least one fluorophore according to the general structure
At least one of R
1
/R
2
, R
2
/R
3
, R
3
/R
4
, R
5
/R
6
, R
6
/R
7
, and/or R
7
/R
8
together form a substituted or unsubstituted cycloalkyl or aryl.
An unexpected cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates to construct 2,3-dihydrobenzofuran spirooxindoles
作者:Kuan Zhang、Huabin Han、Lele Wang、Ziying Zhang、Qilin Wang、Wenjing Zhang、Zhanwei Bu
DOI:10.1039/c9cc07114h
日期:——
An unexpected Michael addition-inspired ring-opening/closure cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates was developed to access new dihydrobenzofuran or dihydrobenzothiophene spirooxindoles in 68–98% yields. This reaction not only provides an expedient and convenient method to assemble dihydrobenzofuran spirooxindoles, but also establishes a new reaction mode of coumarin-3-carboxylates
Enantioselective Addition-Alkylation of α,β-Unsaturated Carbonyls via Bisguanidinium Silicate Ion Pair Catalysis
作者:Wenchao Chen、Esther Cai Xia Ang、Siu Min Tan、Zhijie Chua、Jingyun Ren、Ziqi Yang、Bo Teng、Richmond Lee、Haihua Lu、Choon-Hong Tan
DOI:10.1021/jacs.0c00183
日期:2020.11.11
Silicon hydrides, alkynylsilanes, and alkoxylsilanes were activated by fluoride in the presence of bisguanidinium catalyst to form hypervalent silicate ionpairs. These activated silicates undergo 1,4-additions with chromones, coumarins, and α-cyanocinnamic esters generating enolsilicate intermediates, for a consequent stereoselective alkylation reaction. The reduction-alkylation reaction proceeded