Quinazoline Synthesis via Rh(III)-Catalyzed Intermolecular C–H Functionalization of Benzimidates with Dioxazolones

Abstract

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, and dioxazolone acts as a coupling partner for access to heterocycle.

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…Almost simultaneously, Zhu 300 and Jiao 301 reported two different protocols for the synthesis of quinazolines starting from carboximidates ( Scheme 54A and B ). Both groups relied on the same catalyst, namely [Cp*RhCl 2 ] 2 but used different sources for the nitrogen ending up in position 1 of the quinazoline.…”

Chemical Insights Into the Synthetic Chemistry of Quinazolines: Recent Advances

“…Zhu et al described the [Cp * RhCl 2 ] 2 /AgBF 4 -catalyzed double carbon-nitrogen bond formation sequence for the construction of highly functionalized quinazolines 108 from reaction of benzimidate derivatives 106 with dioxazolone derivatives 107 (Wang J. et al, 2016). In this reaction, dioxazolone derivatives 107 also functioned as an internal oxidizing agent to regulate the catalytic cycle.…”

Copper(I)/Bpy‐Catalyzed C‐2‐H Benzylation of Quinazolin‐4(3H)‐ones with N‐Tosylhydrazones

“…Thus, the development of straightforward access to functionalized quinazolin‐4‐ones have become an attractive area of research. The reported literatures mainly consist of five types of strategies: a) ring‐closure condensation of anthranilic acid derivatives or C–H amidation, b) palladium‐catalyzed carbonylation of 2‐halogenoaniline derivatives or N ‐arylamidines, c) copper‐catalyzed coupling reactions of 2‐halogenobenzoic acid derivatives with amidines, d) rearrangement or cyclization of other heterocycles, e) the Minisci reaction, radical approaches have been recently developed as a strategy to assemble late‐stage alkylation of quinazolinones using carboxylic acids, boronic acids, aldehydes, and alkyltrifluoroborates as alkyl radical precursors. Recently, Zhang and colleagues developed PhI(O 2 CCF 3 ) 2 /NaN 3 ‐promoted cross‐dehydrogenative coupling of quinazolin‐4‐one with nonactivated alkanes to carry out 2‐alkylation of quinazolinones .…”