TY  - GEN
ID  - heidok30609
AV  - public
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/30609/
Y1  - 2022///
CY  - Heidelberg
A1  - Zhang, Cheng
TI  - Gold-Catalyzed Cascade Cyclization of Diazo-tethered Alkynes
N2  - 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 ?-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.
ER  -