The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins
作者:Quan Zhou、Fang-Ting Xiong、Pu Chen、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1039/d1ob01568k
日期:——
by the visible-light-induced acylation/cyclization of alkynoates with various acyl oximecompounds in acetonitrile. The difunctionalization of carbon–carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon–carbon triple bonds, followed by 5-exo-trig cyclization and 1,2-ester migration. This strategy
A new visible-light-mediated radical cyclization of alkynoates with acyl chlorides is described for the one-pot construction of diverse 3-acylcoumarins with high efficiency and selectivity. This method is successful by sequential difunctionalization of an alkynes CC triple bond with the CCl bonds of acyl chloride and aromatic C(sp2)H bonds. The cyclization is proposed to simultaneously form two new
A metal‐free, visible‐light‐promoted direct difunctionalization of alkynoates was achieved undermildconditions. By employing catalytic quantities of the commercially available Eosin Y (EY) as the photocatalyst and tert‐butyl‐hydroperoxide (TBHP) as the oxidant, we developed a radical tandem phosphorylation/cyclization reaction to synthesize various 3‐phosphorylated coumarins with high functional
Visible-light-mediated cascade cyanoalkylsulfonylation/cyclization of alkynoates leading to coumarins <i>via</i> SO<sub>2</sub> insertion
作者:Pu Chen、Zan Chen、Bi-Quan Xiong、Yun Liang、Ke-Wen Tang、Jun Xie、Yu Liu
DOI:10.1039/d1ob00142f
日期:——
alkynoates with cycloketone oxime compounds for the preparation of 3-cyanoalkylsulfonylcoumarins via SO2 insertion is reported. The difunctionalization of carbon–carbon triplebonds includes a radical mechanism and involves the formation of an iminyl radical, ring-opening of the cycloketone, insertion of SO2, addition of the sulfonyl radical to carbon–carbon triplebonds, ipso-cyclization and ester migration
Transfer-catalyst-free biomimetic asymmetric reduction of 3-sulfonyl coumarins with a regenerable NAD(P)H model
作者:Zhou-Hao Zhu、Yi-Xuan Ding、Yong-Gui Zhou
DOI:10.1039/d1cc06896b
日期:——
A novel transfer-catalyst-free biomimetic reduction of the tetrasubstituted olefins 3-sulfonyl coumarins with the chiral and regenerable [2.2]paracyclophane-based NAD(P)Hmodel CYNAM has been developed, affording chiral 3-sulfonyl dihydrocoumarins with excellent enantioselectivities.