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We described a base‐promoted O‐arylation of N3‐hydroxyl quinazolinones with diaryliodonium salts and sequential BF3 ⋅ OEt2 and visible light‐controlled [3,3]‐ or [1,3]‐rearrangements of quinazolinone N−O aryl moieties to prepare a variety of 2‐(quinazolin‐4‐yloxy)phenols and atropisomeric 3‐(2‐hydroxyphenyl)quinazolin‐4‐ones in 44%‐75% yields and 28%‐70% yields, respectively. Mechanistic studies showed that HBF4 generated in situ from BF3 ⋅ Et2O and water served as the catalyst in this process and aryloxyquinazolinium salts are vital intermediates promoting the [3,3]‐ or [1,3]‐rearrangements. The N−O aryl moieties of aryloxyquinazolinium salts were found to undergo solely [3,3]‐rearrangement with heating whereas [1,3]‐rearrangement occurred via a radical process under irradiation of visible light. This method highlights the formation of aryloxyquinazolinium salts based on the use of BF3 ⋅ OEt2 and visible light to prompt [1,3]‐rearrangement generating atropisomeric quinazolinones. [ABSTRACT FROM AUTHOR]

A variety of pseudorutaecarpine derivatives were prepared in good to excellent yields through a gold(I)‐catalyzed selective cyclization and 1,2‐shift of N‐alkynyl quinazolinone‐tethered indoles. Mechanistic study revealed that spiroindolenines generated in situ by cyclization at the the indole C3 position underwent an alkenyl 1,2‐shift to generate pseudorutaecarpine. The reaction proceeds under mild reaction conditions, has a broad substrate scope, good functional group tolerance, and gram‐scalable application. Furthermore, biological evaluation showed that most of the pseudorutaecarpine scaffolds prepared exhibit anti‐inflammatory activity. [ABSTRACT FROM AUTHOR]

A variety of chiral nine‐membered N‐heterocycles were prepared in moderate to good yields with high diastereoselectivity through a silver(I)‐catalyzed [3+2] cycloaddition and [3,3]‐rearrangement of N‐vinyl‐α, β‐unsaturated nitrones and chiral 3‐propioloyloxazolidin‐2‐ones. Experimental studies showed that silver catalyst promoted the cycloaddition and rearrangement process, and the stereochemistry of the nine‐membered N‐heterocycles was controlled via [3,3]‐rearrangement by chiral oxazolidinone‐auxiliary through a boat‐like transition state. Moreover, the obtained nine‐membered N‐heterocycle diastereomers were converted to chiral pyrrolizines with high diastereoselectivity and pyrrolizine carboxylate was obtained in 54% yield with 90% ee by the removal of chiral auxiliary. [ABSTRACT FROM AUTHOR]

We report a Yb(OTf)3‐catalyzed formal [7+2] cycloaddition for the preparation of nine‐membered N‐heterocycles bearing three stereocenters in good yields with high diastereoselectivity through a [3+2] cycloaddition/[3,3]‐rearrangement cascade strategy from N‐vinyl‐α,β‐unsaturated nitrones and methylenecyclopropanes. Preliminary studies show that the Yb(OTf)3 catalyst accelerates the reaction affording kinetically controlled cis‐diastereomers as the major products. The obtained nine‐membered N‐heterocycles are easily converted to useful derivatives for late‐stage modification. [ABSTRACT FROM AUTHOR]