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We report here a study that has revealed two distinct modes of reactivity of azobenzene derivatives (ArNNAr) with benzynes, depending on whether the aryne reacts with a trans - or a cis -azobenzene geometric isomer. Under thermal conditions, trans -azobenzenes engage benzyne via an initial [2 + 2] trapping event, a process analogous to known reactions of benzynes with diarylimines (ArCNAr). This is followed by an electrocyclic ring opening/closing sequence to furnish dihydrophenazine derivatives, subjects of contemporary interest in other fields ( e.g. , electronic and photonic materials). In contrast, when the benzyne is attacked by a cis -azobenzene, formation of aminocarbazole derivatives occurs via an alternative, net (3 + 2) pathway. We have explored these complementary orthogonal processes both experimentally and computationally.
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This content will become publicly available on July 6, 2026
Acid-Catalyzed, Three-Component, Spontaneous Cascades of 1,3-Butadiynyl Propargylic Alcohols as a Route to Phthalan Derivatives
ABSTRACT: We have established an ambient temperature, one-pot, acid-catalyzed, three-component process involving in situ formation of a tetrayne or triyne that spontaneously cyclizes to a benzyne intermediate. This is rapidly captured to give a diverse range of polycyclic phthalan derivatives. Product structural diversity was enhanced by employing various combinations of alkyne substrates and benzyne trapping reagents. This cascade reaction is versatile and efficient and can be effected by a variety of Lewis and Brønsted acid catalysts. Success in an aqueous or even solvent-free environment was demonstrated.
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- Award ID(s):
- 2155042
- PAR ID:
- 10612978
- Publisher / Repository:
- ACS Publications
- Date Published:
- Journal Name:
- ACS Catalysis
- ISSN:
- 2155-5435
- Page Range / eLocation ID:
- 12238 to 12246
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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