I<sub>2</sub>-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO<sub>2</sub> incorporating oxyamination of the CC bond
作者:Sheng Wang、Xiaowei Zhang、Chengyao Cao、Chao Chen、Chanjuan Xi
DOI:10.1039/c7gc01992k
日期:——
oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protectinggroup to regulate the nucleophilicity of the aminogroup and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency
Pd(0)-Catalyzed Alkene Oxy- and Aminoalkynylation with Aliphatic Bromoacetylenes
作者:Stefano Nicolai、Raha Sedigh-Zadeh、Jérôme Waser
DOI:10.1021/jo400254q
日期:2013.4.19
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.