Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals in cross-coupling area is expanding the scope of the coupling partners. In the past decade, diazo compounds (or their precursors N-tosylhydrazones) have emerged as nucleophilic cross-coupling partners in C–C single bond or C═C double bond formations in transition-metal-catalyzed reactions. This type of coupling reaction involves the following general steps. First, the organometallic species is generated by various processes, including oxidative addition, transmetalation, cyclization, C–C bond cleavage, and C–H bond activation. Subsequently, the organometallic species reacts with the diazo substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion to form a C–C bond. The new organometallic species generated from migratory insertion may undergo various transformations. This type of carbene-based coupling has proven...

Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

The cyclopentenone unit is a very powerful synthon for the synthesis of a variety of bioactive target molecules. This is due to the broad diversity of chemical modifications available for the enone structural motif. In particular, chiral cyclopentenones are important precursors in the asymmetric synthesis of target chiral molecules. This Review provides an overview of reported methods for enantioselective and asymmetric syntheses of cyclopentenones, including chemical and enzymatic resolution, asymmetric synthesis via Pauson-Khand reaction, Nazarov cyclization and organocatalyzed reactions, asymmetric functionalization of the existing cyclopentenone unit, and functionalization of chiral building blocks.

Synthesis of Chiral Cyclopentenones.

A Review on the Latest Progress of Chan‐Lam Coupling Reaction

An efficient protocol for facile construction of spiro[indazole-3,3′-indolin]-2′-ones was developed via [3 + 2] dipolar cycloaddition of arynes with 3-diazoindolin-2-ones under mild conditions in excellent yields. Subsequent thermal isomerization of the spiro[indazole-3,3′-indolin]-2′-ones readily afforded indazolo[2,3-c]quinazolin-6(5H)-ones.

Synthesis of Spiro[indazole-3,3′-indolin]-2′-ones via [3 + 2] Dipolar Cycloaddition of Arynes with 3-Diazoindolin-2-ones and Indazolo[2,3-c]quinazolin-6(5H)-ones by Subsequent Thermal Isomerization

An efficient rhodium(III)-catalyzed coupling reaction of N-aryloxyacetamides with 6-diazo-2-cyclohexenones through a cascade redox-neutral C–H functionalization and aromatization has been developed. This novel and scalable transformation provides a straightforward way to construct unsymmetrical ortho-biphenols with broad substrate scope under mild and redox-neutral conditions. The synthetic utility of this approach is demonstrated in the late-stage functionalization of bioactive compounds and the synthesis of an optically active ortho-biphenol.

Rhodium(III)-Catalyzed Cascade Redox-Neutral C–H Functionalization and Aromatization: Synthesis of Unsymmetrical ortho-Biphenols

A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones

Silver(I)-catalyzed ring-contractive rearrangement: a new entry to 5-alkylidene-2-cyclopentenones.

The novel rapid approach is based on a one-pot Pd-catalyzed cross-coupling/aromatization/Ullmann coupling reaction sequence of 6-diazo-2-cyclohexenones with 2-haloiodobenzenes.

A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones.

First total synthesis of (−)-salprzelactone

The rearrangement of 6-diazo-2-cyclohexenones is investigated and found to tolerate substrates bearing alkyl, alkenyl, and aryl substituents with a substituent in position 5 being essential for the formation of the desired products.

Hongyan Zheng

Papers

A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones

Silver(I)-catalyzed ring-contractive rearrangement: a new entry to 5-alkylidene-2-cyclopentenones.

A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones.

First total synthesis of (−)-salprzelactone

Silver(I)-Catalyzed Ring-Contractive Rearrangement: A New Entry to 5-Alkylidene-2-cyclopentenones.