A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused b...A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused benzo[d]azepines bearing three stereogenic centers with moderate to good yields and complete diastereoselectivity. A quinine-catalyzed reaction of yne–allenone esters with nitrones worked well and provided a convergent and regioselective pathway to access these three-dimensional scaffolds from the planar conjugated system. Density functional theory(DFT) calculations have been applied to understand the key process for forming diradical intermediates.展开更多
Comprehensive Summary Developing reactions for the synthesis of 6-6-4 and 6-4 carbocyclic scaffolds with a chiral quaternary center at the bridgehead position is highly desired,considering the existence of such skelet...Comprehensive Summary Developing reactions for the synthesis of 6-6-4 and 6-4 carbocyclic scaffolds with a chiral quaternary center at the bridgehead position is highly desired,considering the existence of such skeletons in natural products with biological activities and the potential of using these molecules for downstream studies in chemical biology and medicinal chemistry.Report here is accessing these target skeletons with high chemo-,regio-and enantio-selectivities through Pd(ll)/chiral N,N'-disulfonyl bisimidazoline(Bim)ligand-catalyzed asymmetric reaction of yne-allenones and arylboronic acids.展开更多
基金financial support from the National Natural Science Foundation of China (Nos. 21871112 and 21971090)。
文摘A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused benzo[d]azepines bearing three stereogenic centers with moderate to good yields and complete diastereoselectivity. A quinine-catalyzed reaction of yne–allenone esters with nitrones worked well and provided a convergent and regioselective pathway to access these three-dimensional scaffolds from the planar conjugated system. Density functional theory(DFT) calculations have been applied to understand the key process for forming diradical intermediates.
基金We are grateful for financial support from the NSFC(Nos.21871112,21971090,and 21933003).
文摘Comprehensive Summary Developing reactions for the synthesis of 6-6-4 and 6-4 carbocyclic scaffolds with a chiral quaternary center at the bridgehead position is highly desired,considering the existence of such skeletons in natural products with biological activities and the potential of using these molecules for downstream studies in chemical biology and medicinal chemistry.Report here is accessing these target skeletons with high chemo-,regio-and enantio-selectivities through Pd(ll)/chiral N,N'-disulfonyl bisimidazoline(Bim)ligand-catalyzed asymmetric reaction of yne-allenones and arylboronic acids.
