Rhodium-catalyzed regio- and enantioselective amination of racemic secondary allylic trichloroacetimidates with N-methyl anilines
作者:Jeffrey S. Arnold、Gregory T. Cizio、Drew R. Heitz、Hien M. Nguyen
DOI:10.1039/c2cc36961c
日期:——
We report the chiral diene ligated rhodium-catalyzed dynamic kinetic asymmetric transformation (DYKAT) of racemic secondary allylic trichloroacetimidates with a variety of N-methyl anilines, providing allylic N-methyl arylamines in high yields, regioselectivity, and enantiomeric excess. The rhodium-catalyzed DYKAT method addresses limitations previously associated with this particular class of aromatic
Rhodium-Catalyzed Regioselective Amination of Secondary Allylic Trichloroacetimidates with Unactivated Aromatic Amines
作者:Jeffrey S. Arnold、Robert F. Stone、Hien M. Nguyen
DOI:10.1021/ol1019025
日期:2010.10.15
The use of unactivated aromatic amines in the rhodium-catalyzed regioselective amination of secondary allylic trichloroacetimidates is explored. The desired N-arylamines are obtained in high yields and regioselectivity, favoring the branched amination products. The presence of the trichloroacetimidate leaving group was found to be critical for successful regioselective amination reactions with unactivated
O — Trichloroacetimidates can be prepared, under mild conditions in high yield and high purity, by reacting the substrate with trichloroacetonitrile in dichloromethane and 50% aqueous potassium hydroxide mixture containing a catalytic amount of tetra-n-butylammonium hydrogen sulfate.
Iridium-Catalyzed Allylic Fluorination of Trichloroacetimidates
作者:Joseph J. Topczewski、Timothy J. Tewson、Hien M. Nguyen
DOI:10.1021/ja2087213
日期:2011.12.7
allylic fluorination method utilizing trichloroacetimidates in conjunction with an iridium catalyst has been developed. The reaction is conducted at room temperature under ambient air and relies on Et(3)N·3HF reagent to provide branched allylic fluorides with complete regioselectivity. This high-yielding reaction can be conducted on a multigram scale and shows considerable functional group tolerance
Rhodium-Catalyzed Sequential Allylic Amination and Olefin Hydroacylation Reactions: Enantioselective Synthesis of Seven-Membered Nitrogen Heterocycles
作者:Jeffrey S. Arnold、Edward T. Mwenda、Hien M. Nguyen
DOI:10.1002/anie.201310354
日期:2014.4.1
Dynamic kinetic asymmetric amination of branched allylic acetimidates has been applied to the synthesis of 2‐alkyl‐dihydrobenzoazepin‐5‐ones. These seven‐membered‐ring aza ketones are prepared in good yield with high enantiomeric excess by rhodium‐catalyzed allylic substitution with 2‐amino aryl aldehydes followed by intramolecularolefin hydroacylation of the resulting alkenals. This two‐step procedure