A newly designed radical cascade involving N-acyl cyanamides is reported. It builds on aromatic homolytic substitutions as intermediate events and leads to complex heteroaromatic structures via an unprecedented radical migration of a substituent on aryl groups of quinazolinones (hydrogen or alkyl). Mechanistic considerations are detailed, which allowed us to devise fine control over the domino processes
Peroxide-Mediated Oxidative Radical Cyclization to the Quinazolinone System: Efficient Syntheses of Deoxyvasicinone, Mackinazolinone and (±)-Leucomidine C
作者:Luis D. Miranda、Jazmín García-Ramírez
DOI:10.1055/s-0040-1705975
日期:2021.4
An efficient protocol for obtaining fused quinazolinones through an oxidative free-radical cyclization under metal- and tin-free conditions is described. The oxidativecyclization of various N-3-ω-iodoalkyl derivatives to provide tricyclic systems using dicumyl peroxide as the sole reagent is studied. The method then is employed for the syntheses of 5-, 6-, and 7-membered fused quinazolinone analogues
Metal-Free Photoinduced Hydrocyclization of Unactivated Alkenes toward Ring-Fused Quinazolin-4(3<i>H</i>)-ones via Intermolecular Hydrogen Atom Transfer
作者:Zixian Yang、Xian Wu、Jie Zhang、Jin-Tao Yu、Changduo Pan
DOI:10.1021/acs.orglett.3c00329
日期:2023.3.17
of unactivated alkenes was developed using 3CzClIPN as the photocatalyst to generate substituted α-methyldeoxyvasicinones and α-methylmackinazolinones in moderate to good yields. An intermolecular hydrogen atom transfer with THF as the hydrogen source was involved. Mechanism studies indicated that the intramolecular addition of the in situ formed aminal radical to the unactivated alkene generated the
Ag‐Catalyzed Remote Dehydrogenative‐coupling of Unactivated C(sp<sup>3</sup>)−H Alcohols with Quinazolines for the Synthesis of δ‐Hydroxylalkyl Substituted Quinazolines in Aqueous Media
An efficient silver-catalyzed δ-regioselective unactivated C(sp3 )−H of free alcohols dehydrogen-coupling with quinazolines for the synthesis of δ-hydroxylalkyl substituted quinazolines in aqueous medium has been developed. This protocol provides a platform to access divergent functionalizations of quinazolines and quinazolinones to meet the growing needs for screening.
Photocatalytic alkenes to ring-fused quinazolin-4(3H)-ones via proton-transfer shuttle using TFA
作者:Xianming Wang、Xinhan Li、Luqian Zou、Qinli Lu、Chenggang Zao、Qingling Ou、Ruifeng Fan、Jianbin Xu、Baomin Fan
DOI:10.1016/j.tet.2024.133990
日期:2024.5
system is reported that enables intramolecularhydroarylation of unactivatedalkenesvia a proton transfer shuttle using TFA, providing a concise access to the formation of pyrroloquinazolinone and pyridyquinazolinone products in moderate to good yields. Mechanistic studies revealed that the protonated quinazolinone is the key radical precursor mediating the intramolecular cyclization reaction.