title: Gold-Catalyzed Cascade Cyclization of Diazo-tethered Alkynes
creator: Zhang, Cheng
subject: ddc-540
subject: 540 Chemistry and allied sciences
description: In Chapter 2, a gold-catalyzed domino annulation of diazo-tethered alkynes with nitriles proceeds through a sequential 6-endo-dig cyclization/nitrile insertion/C-H functionalization. This protocol offers a general and modular strategy for the rapid assembly of benzophenanthridine derivatives with a broad functional-group tolerance. Moreover, this methodology, using readily available nitriles as the nitrogen source, represent a versatile platform for the construction of benzophenanthridine frameworks.     In Chapter 3, an unprecedented dichotomy in the regioselectivity of carbohydroxylation of diazo-tethered alkynes was observed. The gold-catalyzed 6-endo-dig cyclization leads to the quinoid-carbene species, terminated by direct O-H insertion under additive-free conditions, while the reaction in the presence of Et3N(HF)3 undergoes an O-H ortho-insertion of carbene/rearrangement to give the dihydroxynaphthalene isomers as the major products.     In Chapter 4, the gold-catalyzed carbofluorination of diazo-tethered alkynes provides a facile, efficient, and atom-economical route to α-fluoronaphthalene derivatives. An intermediate endocyclic gold carbene, generated by an intramolecular 6-endo-dig cyclization, promotes a carbene H-F insertion to afford the desired products.
date: 2022
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/30609/1/PhD_Thesis_Cheng_Zhang.pdf
identifier: DOI:10.11588/heidok.00030609
identifier: urn:nbn:de:bsz:16-heidok-306098
identifier:   Zhang, Cheng  (2022) Gold-Catalyzed Cascade Cyclization of Diazo-tethered Alkynes.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/30609/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng