A modified Bischler-Napieralski procedure for the synthesis of 3-aryl-3,4-dihydroisoquinolines
摘要:
A modification of the Bischler-Napieralski reaction for the cyclization of (1,2-diphenylethyl)amides to the 3-aryl-3,4-dihydroisoquinolines is presented. Elimination of the amide group as the nitrile via the retro-Ritter reaction is avoided by its conversion to an N-acyliminium intermediate with oxalyl chloride-FeCl3. Removal of the oxalyl group in refluxing MeOH-sulfuric acid provides the 3,4-dihydroisoquinolines in moderate to high yields. The method is also highly effective with (2-phenylethyl)amides.
Synergistic Catalysis between a Dipeptide Phosphonium Salt and a Metal‐Based Lewis Acid for Asymmetric Synthesis of
<i>N</i>
‐Bridged [3.2.1] Ring Systems
作者:Yuan Chen、Jiajia He、Cheng Zhuang、Zanjiao Liu、Kai Xiao、Zhishan Su、Xiaoyu Ren、Tianli Wang
DOI:10.1002/anie.202207334
日期:2022.9.19
method for asymmetric construction of N-bridged [3.2.1] rings by a phosphoniumsalt/silver co-catalyzed cyclization has been developed. This route affords fluorine-installed tropane derivatives in excellent stereoselectivities. The mechanistic results revealed that the silver nitrite was installed on the phosphoniumsalt via hydrogen bonding and simultaneously activated the dipole, in a “sandwich” reaction