Styrene as 4π-Component in Zn(II)-Catalyzed Intermolecular Diels–Alder/Ene Tandem Reaction
作者:Min Zheng、Feng Wu、Kai Chen、Shifa Zhu
DOI:10.1021/acs.orglett.6b01511
日期:2016.8.5
A mild Zn-catalyzed intermolecular Diels–Alder/ene tandemreaction with styrene as a 4π-component is reported. A variety of dihydronaphthalene products could be prepared in moderate to good yields. Moreover, a combination of DFT calculations and experiments was performed to further understand the mechanism of this unique tandemreaction.
Ru(II)- and Os(II)-Induced Cycloisomerization of Phenol-Tethered Alkyne for Functional Chromene and Chromone Complexes
作者:Sze-Wing Ng、Sheung-Ying Tse、Chi-Fung Yeung、Lai-Hon Chung、Man-Kit Tse、Shek-Man Yiu、Chun-Yuen Wong
DOI:10.1021/acs.organomet.0c00048
日期:2020.4.27
Diphosphine-containing Ru(II)/Os(II)–chromene and −chromone complexes were synthesized from reactions between phenol ynone HC≡C(C═O)(o-C6H4OH) and cis-[Ru/Os(dppm)2Cl2] (dppm = 1,1-bis(diphenylphosphino)methane). The structures of these complexes in the solid state along with their pH-dependent chromene/chromone equilibrium behavior in aqueous medium were investigated. The cis–trans equilibration in
Metalated Chromene and Chromone Complexes: pH Switchable Metal-Carbon Bonding Interaction, Photo-triggerable Chromone Delivery Application, and Antioxidative Activity
作者:Sze-Wing Ng、Lai-Hon Chung、Chi-Fung Yeung、Hoi-Shing Lo、Hau-Lam Shek、Tian-Shu Kang、Chung-Hang Leung、Dik-Lung Ma、Chun-Yuen Wong
DOI:10.1002/chem.201705450
日期:2018.2.6
metalated chromene and chromone complexes synthesized through transition‐metal‐mediated cyclization of phenol‐tethered ynone. These unprecedented metalated heterocyclic compounds exhibit remarkable features, such as pH‐switchable metal–carbon bonding interactions, photo‐triggerable release of organic chromone upon visible‐light irradiation, and superior antioxidative property to their organic analogue
A highly diastereo- and enantioselectivering-opening/cycloaddition reaction of cyclobutenones with 2-hydroxyacetophenones or salicylaldehyde was achieved by employing a chiral N,N′-dioxide-scandium(III) complex as the catalyst. It provided various 3-phenylvinyl-4-hydroxy-dihydrocoumarins in good yields (up to 92%), high enantioselectivities (up to 93% ee), and excellent diastereoselectivities (>19:1
Unified Approach to (Thio)chromenones via One-Pot Friedel–Crafts Acylation/Cyclization: Distinctive Mechanistic Pathways of β-Chlorovinyl Ketones
作者:Hun Young Kim、Eunsun Song、Kyungsoo Oh
DOI:10.1021/acs.orglett.6b03348
日期:2017.1.20
method to chromenones and thiochromenones has been developed using a one-pot Friedel–Craftsacylation of alkynes with suitably substituted benzoyl chlorides. This unified approach to (thio)chromenones is readily applicable to aryl- and alkylalkynes where the stereochemically well-defined β-chlorovinyl ketone intermediates undergo distinctively different cyclization pathways. The ready availability