Palladium-catalyzed intramolecular aminoiodination of alkenes using molecular oxygen as oxidant
作者:Lu Chen、Xianglin Luo、Yibiao Li
DOI:10.1007/s00706-016-1819-2
日期:2017.5
AbstractMolecular oxygen as oxidant to promote palladium-catalyzedintramolecular aminoiodination of alkenes has been described. The yields are excellent and show high exo-selectivities with various substrates. Graphical abstract
A general and efficient intramolecular halo-amination of unactivatedalkenes for the synthesis of various halogenated N-heterocycles was developed via electrochemical anodic oxidation. This protocol proceeds in a simple undivided cell by employing LiI or LiBr as redox mediums and halogen sources. A wide range of halogenated N-heterocycles, including three-, five-, and six-membered N-heterocycles were
Practical and Convenient Synthesis of <i>N</i>-Heterocycles: Stereoselective Cyclization of <i>N</i>-Alkenylamides with <i>t</i>-BuOI under Neutral Conditions
[Structure: see text] tert-Butylhypoiodite (t-BuOI) was found to be a powerful reagent for the cyclization of N-alkenylamides leading to a variety of N-heterocycles under extremely mild conditions. When N-alkenylsulfonamides were employed in the reaction, three- to six-membered saturated N-heterocycles were obtained in good to excellent yields with complete stereoselectivity. The method was applicable
MnI2-catalyzed regioselective intramolecular iodoamination of unfunctionalized olefins
作者:Hui Sun、Bin Cui、Gong-Qing Liu、Yue-Ming Li
DOI:10.1016/j.tet.2016.09.038
日期:2016.11
MnI2-catalyzed intramolecular iodoamination of unfunctionalized olefins was reported. Interaction of MnI2 with N-alkenyl amine/sulfonamide gave NRMnI which produced a CH2MnI intermediate via intramolecular aminometallation of CC double bond. Reductive elimination of CH2I from CH2MnI produced iodomethyl heterocycle with the release of Mn(0) which was confirmed by XPS and XRD experiments.
A new protocol for the cyclization of N-alkenylamides using chloramine-T and iodine is described. When N-alkenylsulfonamides are treated with chloramine-T and iodine, three- to six-membered N-heterocycles are obtained with complete stereoselectivity. The method is compatible with the cyclization of the allylbenzamide or allylbenzthioamide to afford an oxazoline or thiazoline derivative, respectively. Mechanistic studies indicate that the chloramine-T/I-2 system functions as an effective iodonium species. (c) 2006 Elsevier Ltd. All rights reserved.