Pd(0)-Catalyzed Alkene Oxy- and Aminoalkynylation with Aliphatic Bromoacetylenes
摘要:
Tetrahydrofurans and pyrrolidines are among the most important heterocycles found in bioactive compounds. Cyclization-functionalization domino reactions of alcohols or amines onto olefins,constitute one of the most efficient methods to access them. In this context oxy- and aminoalkynylation are especially important reactions because of the numerous transformations possible with the triple bond of acetylenes yet these methods have been limited to the use of silyl protected acetylenes. Herein we report the first palladium-catalyzed oxy- and aminoalkynylation using aliphatic bromoalkynes which proceeded with high diastereoselectivity and functional group tolerance. A one-pot hydrogenation of the triple bond gave then access to alkyl-substituted tetrahydrofurans and pyrroldines. Finally a detailed study of the side products formed during the reaction gave a first insight into the reaction mechanism.
One-Pot Three-Component Synthesis of Vicinal Diamines via In Situ Aminal Formation and Carboamination
作者:Ugo Orcel、Jerome Waser
DOI:10.1002/anie.201607318
日期:2016.10.4
A synthesis of vicinal diamines via in situ aminalformation and carboamination of allyl amines is reported. Employing highly electron‐poor trifluoromethyl aldimines in their stable hemiaminal form was key to enable both a fast and complete aminalformation as well as the palladium‐catalyzed carboamination step. The conditions developed allow the introduction of a wide variety of alkynyl, vinyl, aryl