A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 176

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML

File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

Lewis acid-catalyzed [3 + 2] annulations of oxindole based spirocyclic donor-acceptor cyclopropanes with ynamides. | LitMetric

Lewis acid-catalyzed [3 + 2] annulations of oxindole based spirocyclic donor-acceptor cyclopropanes with ynamides.

Org Biomol Chem

Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, No. 59 Hudong Road, Ma'anshan 243002, China.

Published: November 2021

[3 + 2] annulations of oxindole based spirocyclic donor-acceptor cyclopropanes and ynamides catalyzed by copper triflate have been developed for the synthesis of biologically important spirocyclopenteneoxindoles. These reactions tolerated a wide scope of substrates and provided the desired products in good to high yields (up to 90%) with up to >40 : 1 diastereoselectivities under mild conditions.

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1ob01922hDOI Listing

Publication Analysis

Top Keywords

annulations oxindole
8
oxindole based
8
based spirocyclic
8
spirocyclic donor-acceptor
8
donor-acceptor cyclopropanes
8
cyclopropanes ynamides
8
lewis acid-catalyzed
4
acid-catalyzed annulations
4
ynamides annulations
4
ynamides catalyzed
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!