An efficient and highly stereoselective synthetic method to access polycyclic chromanes has been achieved through organocatalyzed one-pot step-wise reactions involving 2-hydroxycinnamaldehydes,2-aminochalcones,and mal...An efficient and highly stereoselective synthetic method to access polycyclic chromanes has been achieved through organocatalyzed one-pot step-wise reactions involving 2-hydroxycinnamaldehydes,2-aminochalcones,and malononitrile as substrates.The reactions underwent a quintuple process by aza-Michael/Michael/Knoevenagel/oxa-Michael/aldol-type reaction in sequence to give products bearing 3 new generated rings and 5 chiral centers in moderate to quantitative yields with excellent stereoselectivities.展开更多
Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridg...Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones.Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of t BuOK in commercially available EtOH solvent at 60℃.Notably,the simple reactions can be run on a gram scale.Mechanistically,bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.展开更多
The photochemical reactions of active methylene containing such as fluorene, diphenymethane(DPM), di(1 naphthyl)methane (DNM) and triphenymethane(TPM) with N bromosuccinimide (NBS) were investigated The results show t...The photochemical reactions of active methylene containing such as fluorene, diphenymethane(DPM), di(1 naphthyl)methane (DNM) and triphenymethane(TPM) with N bromosuccinimide (NBS) were investigated The results show that monobromo derivatives can be selectively obtained when the ratio of NBS to a substrate is 1 1∶1 and that the reactivities of the substrates toward photochemical reaction are DNM > Fluorene> DPM > TPM The reaction mechanisms were also展开更多
基金supported by the Advanced Talents Incubation Program of Hebei University(521000981411)the National Nature Science Foundation of China(82273792),Science Research Project of Hebei Education Department(QN2021023)+2 种基金the Natural Science Interdisciplinary Research Program of Hebei_University(DXK201913)High-throughput Intelligent Integrated Lung Cancer Targeted Drug Development Innovation Team Project(IT2023c01)the Excellent Youth Research Innovation Team of Hebei University(QNTD202406).
文摘An efficient and highly stereoselective synthetic method to access polycyclic chromanes has been achieved through organocatalyzed one-pot step-wise reactions involving 2-hydroxycinnamaldehydes,2-aminochalcones,and malononitrile as substrates.The reactions underwent a quintuple process by aza-Michael/Michael/Knoevenagel/oxa-Michael/aldol-type reaction in sequence to give products bearing 3 new generated rings and 5 chiral centers in moderate to quantitative yields with excellent stereoselectivities.
基金National Natural Science Foundation of China(NSFC,Nos.21772032,21877206,and 22101074)the 111 Project(No.D17007)+3 种基金Excellent Youth Foundation of Henan Scientific Committee(No.222300420012)China Postdoctoral Science Foundation(No.2019M660173)the Natural Science Foundation of Henan Province(No.202300410233)Henan Key Laboratory of Organic Functional Molecules and Drug Innovation for financial support。
文摘Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones.Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of t BuOK in commercially available EtOH solvent at 60℃.Notably,the simple reactions can be run on a gram scale.Mechanistically,bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.
文摘The photochemical reactions of active methylene containing such as fluorene, diphenymethane(DPM), di(1 naphthyl)methane (DNM) and triphenymethane(TPM) with N bromosuccinimide (NBS) were investigated The results show that monobromo derivatives can be selectively obtained when the ratio of NBS to a substrate is 1 1∶1 and that the reactivities of the substrates toward photochemical reaction are DNM > Fluorene> DPM > TPM The reaction mechanisms were also
