Aza-Reformatsky Reaction Promoted by Catalytic Samarium Diiodide: Synthesis of β-Amino Esters or Amides
作者:Humberto Rodríguez-Solla、Ainhoa Díaz-Pardo、Carmen Concellón、Vicente del Amo
DOI:10.1055/s-0034-1378229
日期:——
esters or amides has been achieved from moderate to high yields from the reaction of imines and α-halo esters or amides promoted by catalytic amounts of samariumdiiodide in the presence of magnesium turnings as co-reductant. A mechanism is proposed to explain this catalytic samarium(II)-promoted aza-Reformatsky reaction.
β-氨基酯或酰胺的合成已通过亚胺和α-卤代酯或酰胺在镁屑作为助还原剂存在下催化量的二碘化钐促进的反应实现中等至高产率。提出了一种机制来解释这种催化钐 (II) 促进的 aza-Reformatsky 反应。
The Addition Reaction of Samarium Enolates and 2-Haloenolates Derived from Esters, and Amides to Imines. Totally Stereoselective Synthesis of Enantiopure 3,4-Diamino Esters or Amides
addition reaction of samarium enolates and 2-haloenolates derived from esters and amides to imines takes place in an efficient manner. A novel protocol to perform the addition reaction of samarium enolates derived from esters or amides to chiral 2-aminoimines, with total stereoselectivity and without racemization, is also reported. The use of samarium enolates in place of other classic metallic enolates
An Efficient Prins Cyclization for Stereoselective Synthesis of Tetrahydropyran from Imines and Homoallyl Alcohols
作者:Congrong Liu、Daojuan Cheng、Fulai Yang
DOI:10.1002/cjoc.201400450
日期:2014.11
An unprecedented protocol has been developed for the efficientsynthesis of substituted tetrahydropyrans via a bismuth‐promoted Prinscyclization of imines with homoallylalcohols. In the presence of 40 mol% BiCl3, a wide variety of imines react smoothly with homoallylalcohols at room temperature to give the corresponding 4‐chlorotetrahydropyran derivatives in good to excellent yields.
Aziridination and unpredicted homologation reaction of N-sulfonylimines were achieved easily with a very simple, rapid and mild procedure through the use of diazomethane without the presence of any catalyst. The method represents an attractive alternative to metal-catalyzed processes.
Stereoselective Synthesis of Isoquinuclidines through an Aza-[4 + 2] Cycloaddition of Chiral Cyclic 2-Amidodienes
作者:Li-Chao Fang、Richard P. Hsung
DOI:10.1021/ol500390a
日期:2014.3.21
A highly stereoselective aza-[4 + 2] cycloaddition of chiral cyclic 2-amidodienes with N-sulfonyl aldimines is described. While this Lewis acid promoted heterocycloaddition provides an efficient strategy for constructing optically enriched isoquinuclidines, it is mechanistically intriguing. The cycloaddition favored the endo-II pathway in the absence of a viable bidentate coordination. This represents