Co(III)-Catalyzed Synthesis of Quinazolines via C–H Activation of <i>N</i>-Sulfinylimines and Benzimidates
作者:Fen Wang、He Wang、Qiang Wang、Songjie Yu、Xingwei Li
DOI:10.1021/acs.orglett.6b00227
日期:2016.3.18
as a synthon of nitriles, and subsequent coupling with arenes such as N-sulfinylimines and benzimidates bearing a functionalizable directing group provided facile access to two classes of quinazolines under Co(III)-catalysis.
An efficient double C–N bond formation sequence to prepare highly substituted quinazolines utilizing benzimidates and dioxazolones under the catalytic redox-neutral [Cp*RhCl2]2/AgBF4 system, where dioxazolones could work as an internal oxidant to maintain the catalytic cycle, is reported. N-Unsubstituted imine not only acts as a directing group but also functions as a nucleophile in postcoupling cyclization
Overcoming the Limitations of C−H Activation with Strongly Coordinating N-Heterocycles by Cobalt Catalysis
作者:Hui Wang、Mélanie M. Lorion、Lutz Ackermann
DOI:10.1002/anie.201603260
日期:2016.8.22
Stronglycoordinating nitrogen heterocycles, including pyrimidines, oxazolines, pyrazoles, and pyridines, were fully tolerated in cobalt‐catalyzed C−H amidations by imidate assistance. Structurally complex quinazolines are thus accessible in a step‐economic manner. Our findings also establish the relative powers of directing groups in cobalt(III)‐catalyzed C−H functionalization for the first time.
We developed an unprecedented iridium-catalyzed C−H activation/cyclization to synthesize isoquinoline compounds efficiently using ethyl benzimidate and N-alkoxyamides. This reaction has the advantages of wide substrate adaptability, short reaction times and no need for an inert atmosphere. In addition, some drug molecules smoothly converted into aminating reagents, reacted efficiently and afforded
A Comparative Investigation: Group 9 Cp*M(III)-Catalyzed Formal [4 + 2] Cycloaddition as an Atom-Economic Approach to Quinazolines
作者:Xiaoming Wang、Andreas Lerchen、Frank Glorius
DOI:10.1021/acs.orglett.6b00716
日期:2016.5.6
A comparative study on the catalytic activity of different group 9 [Cp*M(III)] complexes in the formal [4 + 2] cycloaddition of arenes with rarely explored free imines and dioxazolones for the construction of multisubstituted quinazolines is reported herein. This investigation revealed that the cobalt catalyst is uniquely suited to this transformation due to its strong Lewis acidity and high sensitivity