The HDDA-derived benzyne intermediate was captured by oxazolines based on the addition reaction of benzyne to the CN double bond. Benzoxazepine derivatives, fused benzoxazepine derivatives, and fully substituted indoles are synthesized in one step. The reaction does not require any catalyst or additives. Possible reaction mechanisms are presented.

An efficient asymmetric hydrogenation of racemic γ-substituted cyclic β-ketoesters via dynamic kinetic resolution to provide chiral cyclic β-hydroxy esters with three contiguous stereocenters is reported. Using a chiral spiro iridium catalyst (R)-5 (Ir-SpiroSAP), a series of racemic γ-aryl/alkyl substituted cyclic β-ketoesters were hydrogenated to the corresponding chiral cyclic βhydroxy esters in high yields (84−97%) with good to excellent enantioselectivities (69−>99% ee) and cis,cis-selectivities (up to >99:1).

Here we report a capture reaction of hexadehydro–Diels–Alder derived benzyne with various substituted oxazoles. With methyl, hydrogen or phenyl as the substituent at 2-position of oxazole, we obtained epoxyanthracene derivative and dicarbonylation on benzene ring. The reaction does not require any catalyst and additive. The mechanism behind the reaction was investigated. The obtained polycyclic product structure has potential application value in optoelectronic materials. The availability of dicarbonylated arene implies the uniqueness of HDDA benzyne reaction compared with traditional benzyne.

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Comprehensive SummaryThe design and synthesis of spirochromane‐4,1'‐indan‐2‐one‐7'‐ol (SCIOL) and its application for synthesizing chiral monophosphinite ligands are reported. The synthesis features a tandem double Friedel‐Crafts reaction/lactonization to construct the spiro framework and the desired racemic SCIOL was obtained via 6 steps with a total yield of 44.5%. Using an inclusion resolution with N‐benzylcinchonidinium chloride, the optical SCIOL could be obtained in good yields on a gram scale. The preliminary studies indicated that the corresponding chiral spiro monophosphinite ligands exhibit high catalytic activity and enantioselectivity (up to 94% ee) in the rhodium‐catalyzed asymmetric hydrogenation of N‐acetyl dehydroamino esters. These outcomes highlight the significant potential of SCIOL as a useful framework for the development of chiral spiro ligands.This article is protected by copyright. All rights reserved.