Reaction of Arynes with Vinylogous Amides: Nucleophilic Addition to the ortho-Quinodimethide Intermediate
摘要:
The reaction of arynes with vinylogous amides containing no free N-H bonds proceeds in a [2 + 2] cycloaddition fashion at ambient temperature. The electronic properties of the vinylogous amides allow for the cycloadducts undergoing a facile ring-opening process, leading to electronically biased ortho-quinodimethide intermediates. Subsequent nucleophilic addition with alcohols affords 2-substituted benzaldehydes or ketones.
The C=C Bond Decomposition Initiated by Enamine‐Azide Cycloaddition for Catalyst‐ and Additive‐Free Synthesis of
<i>N</i>
‐Sulfonyl Amidines
作者:Xixi Zheng、Jie‐Ping Wan
DOI:10.1002/adsc.201901054
日期:2019.12.17
The chemo‐selective synthesis of N‐sulfonyl amidines is realized via the decomposition of the enamine C=C bond of enaminoesters through an in situ generated triazoline intermediate. Control experiments prove that the electron withdrawing ester group in the enamine component is crucial in inducing the chemo‐selective formation of amidines. The method is featured with high efficiency and sustainability