A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new（（Rax）-BuP）/（R,R）-DPEN-Ru（Ⅱ） complex catalyst system.The hydrogenation ...A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new（（Rax）-BuP）/（R,R）-DPEN-Ru（Ⅱ） complex catalyst system.The hydrogenation of 2-methylacetophenone in n-butanol （t-BuOK/Ru =45.6/1,S/C = 500,20 atm.of H2,20℃,48 h） afforded（S）-1-（2＇-methylphenyl）ethanol in 92%ee and〉99% conversion.展开更多
An oxidative annulation of 2-arylidene-1,3-indanediones with Meldrum's acid has been developed for the divergent syntheses of spirolactones with a spirocenter located at theγ-position with respect to the carbonyl...An oxidative annulation of 2-arylidene-1,3-indanediones with Meldrum's acid has been developed for the divergent syntheses of spirolactones with a spirocenter located at theγ-position with respect to the carbonyl group.This heteroannulation protocol tolerates various functional groups and delivers moderate-to-good product yields.Interestingly,the reaction outcomes are exclusively controlled by the reaction oxidant/medium.This annulation strategy can also be executed in the flow system with decent product yields.Control experiments revealed that the reaction proceeds via a radical tandem annulation pathway.展开更多
Sonogashira cross-coupling protocol,typically showing the reaction between aryl/vinyl halide and terminal alkyne,has been a widely used protocol for constructing C(sp2)-C(sp)bond.The resulting internal alkynes are hig...Sonogashira cross-coupling protocol,typically showing the reaction between aryl/vinyl halide and terminal alkyne,has been a widely used protocol for constructing C(sp2)-C(sp)bond.The resulting internal alkynes are highly versatile for reaching differently function-alized alkyne-containing scaffolds or serving as valuable synthetic synthons to many other functional groups.It is worth noting that products originated from this coupling reaction are mostly applicable to be transformed into corresponding Z-alkene,alkane,or het-erocyclic moieties in natural product syntheses.The reaction conditions and catalyst systems are able to be tweaked in order to facil-itate the activation of steric hindered and/or electron-rich electrophiles.Pd-catalyzed copper-free Sonogashira coupling reaction has caught increasing attention as the improved method can be more environmentally friendly.What is more,the conditions of the cou-pling reaction can be readily amended to allow the fusion of other carbonylation or decarboxylation step in the catalytic cycle,and thus allow more complex yet versatile convergent synthesis to proceed in an operationally simple one-pot manner.展开更多
基金the National Natural Science Foundation of China(Nos.20343005,20473107,20673130,and 20773147)the Hong Kong PolyU Joint Supervision Scheme(A-PH78) for financial support.
文摘A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new（（Rax）-BuP）/（R,R）-DPEN-Ru（Ⅱ） complex catalyst system.The hydrogenation of 2-methylacetophenone in n-butanol （t-BuOK/Ru =45.6/1,S/C = 500,20 atm.of H2,20℃,48 h） afforded（S）-1-（2＇-methylphenyl）ethanol in 92%ee and〉99% conversion.
基金the National Natural Science Foundation of China(No.22078150)the Natural Science Foundation of Jiangsu Province,Frontier Project(No.BK20212003)for their financial support+2 种基金the RGC of Hong Kong(No.14308922)the Guangdong Research Fund(No.2022A1515010955)CUHK Direct Grant(No.4053559)。
文摘An oxidative annulation of 2-arylidene-1,3-indanediones with Meldrum's acid has been developed for the divergent syntheses of spirolactones with a spirocenter located at theγ-position with respect to the carbonyl group.This heteroannulation protocol tolerates various functional groups and delivers moderate-to-good product yields.Interestingly,the reaction outcomes are exclusively controlled by the reaction oxidant/medium.This annulation strategy can also be executed in the flow system with decent product yields.Control experiments revealed that the reaction proceeds via a radical tandem annulation pathway.
基金the Research Grants Council of Hong Kong(GRF:14308121)cUHK Direct Fund(4053503)for financial support.We also thank the Guangdong Basic and Applied Basic Research Foundation(2022A1515010955)+3 种基金Shenzhen Virtual University Park Fund(2021Szvup147)for their supportthankful for the Innovation and Technology Commission(HKSAR,China)to the State Key Laboratory of Synthetic Chemistrythank Guangdong Province Zhu Jiang Talents Plan(Project code:2016ZT06C090)Guangzhou City Talents Plan(Project code:CYLJTD-201609)for their support.
文摘Sonogashira cross-coupling protocol,typically showing the reaction between aryl/vinyl halide and terminal alkyne,has been a widely used protocol for constructing C(sp2)-C(sp)bond.The resulting internal alkynes are highly versatile for reaching differently function-alized alkyne-containing scaffolds or serving as valuable synthetic synthons to many other functional groups.It is worth noting that products originated from this coupling reaction are mostly applicable to be transformed into corresponding Z-alkene,alkane,or het-erocyclic moieties in natural product syntheses.The reaction conditions and catalyst systems are able to be tweaked in order to facil-itate the activation of steric hindered and/or electron-rich electrophiles.Pd-catalyzed copper-free Sonogashira coupling reaction has caught increasing attention as the improved method can be more environmentally friendly.What is more,the conditions of the cou-pling reaction can be readily amended to allow the fusion of other carbonylation or decarboxylation step in the catalytic cycle,and thus allow more complex yet versatile convergent synthesis to proceed in an operationally simple one-pot manner.
