Catalyst-dependent oxidative cyclization of diynes with pyridine N-oxides is achieved using an amide directing group. Non-polarized and aminated alkyne could be selectively activated by copper and gold, thus leading to divergent synthesis of a range of pyrroles and dihydroindeno[1,2-c]pyrrol-3(2H)-ones. It should be noted that this difference might be attributed to the multicoordinated Cu center and the linearly aligned dicoordinated Au center.

Cu(I)- and Au(I)-catalyzed regioselective oxidation of diynes: divergent synthesis of N-heterocycles

The gold-catalyzed reaction between benzofuroxans, functioning as nitrene transfer reagents, and N-allylynamides leads to 3-azabicyclo[3.1.0]hexan-2-imines. This highly selective annulation proceeds smoothly under mild conditions (5 mol % Ph3PAuNTf2, PhCl, 60 °C) and exhibits high functional group tolerance (21 examples, ≤96% yields). The obtained cyclopropanated products represent a useful synthetic platform with an easily modulated substitution pattern as illustrated by their postmodifications. Intramolecular cyclopropanation of gold α-imino carbene intermediates is suggested as a key step of the catalytic cycle.

Gold-Catalyzed Nitrene Transfer from Benzofuroxans to N-Allylynamides: Synthesis of 3-Azabicyclo[3.1.0]hexanes.

An efficient gold-catalyzed oxidative cyclization of amide-alkynes is developed. A series of functionalized γ-lactams are easily accessed by employing this strategy. The tandem reaction proceeds through alkyne oxidation, carbene/alkyne metathesis, and donor/donor carbene oxidation.

Gold-catalyzed oxidative cyclization of amide-alkynes: access to functionalized γ-lactams.

Described herein is a novel copper-catalyzed multifunctionalization of alkyne-tethered indoles, allowing practical and efficient synthesis of a diverse array of valuable dihalogen-substituted spiroindoles containing tetrasubstituted alkenes which can be further...

Copper Catalyzed Dearomatization by Michael-Type Addition of Indolyl Ynones: Divergent Synthesis of Functionalized Spiroindoles and Cyclopenta[c]quinolin-3-ones

Dan Zhao

Papers

Copper(I)-Catalyzed Enyne Oxidation/Cyclopropanation: Divergent and Enantioselective Synthesis of Cyclopropanes.