A Stereocontrolled Synthesis of (±)-Xenovenine via a Scandium(III)-Catalyzed Internal Aminodiene Bicyclization Terminated by a 2-(5-Ethyl-2-thienyl)ethenyl Group
摘要:
A highly diastereoselective binary hydroamination of a 5-amino-1,8-diene containing a 2-(5-ethyl-2-thienyl)ethenyl terminator has been utilized in an efficient synthesis of (+/-)-xenovenine (1). A pronounced rate enhancement was observed for cyclization onto the 2-(heteroaromatic)ethenyl group in comparison to a simple 1,2-disubstituted alkene.
α-Selective Allylation of Isatin Imines Using Metallic Barium
作者:Akira Yanagisawa、Seiya Yamafuji、Toshiki Sawae
DOI:10.1055/s-0035-1561450
日期:——
Barbier-type allylation of isatin imines with allylicchlorides was achieved by using metallic barium as the promoter. Various α-allylated 3-amino-2-oxindoles were synthesized from the corresponding allylicchlorides and isatin imines. The double-bond geometry of allylicchlorides was retained throughout the reaction. An arylic bromide or iodide functionality of the products was robust to metalation under the
The hydroallylation of allenes was developed by employing a hydrosilane and allylchlorides in the presence of a copper catalyst. The reaction provided (E)-1,5-dienes mainly in good to high yields.
cycloadditions of 2‐nitrosopyridine with various allylstannanes give 4‐stannyl‐substituted isoxazolidines. The use of [Cu(MeCN)4]PF6, in combination with a Walphos ligand, leads to excellent enantioselectivies and high yields. With cis‐2‐alkenylstannanes as nucleophiles, 3‐alkyl‐4‐stannyl‐substituted isoxazolidines are formed with excellent diastereo‐ and enantioselectivities.