Cu(I)-Catalyzed Coupling and Cycloisomerization of Diazo Compounds with Terminal Yne-Alkylidenecyclopropanes: Synthesis of Functionalized Cyclopenta[b]naphthalene Derivatives

Gold(I)-Mediated Cyclizations of Triene-Yne Systems: An Easy Access to Cyclopenta-Fused Anthracenes

The direct synthesis of cyclopenta-fused anthracenes (CP-anthracenes) through a gold(I)-catalyzed cyclization reaction of easily available triene-yne systems bearing a benzofulvene substructure, is reported. The targets are of great interest due to the potential use as organic materials and the preparation of these compounds is gaining huge importance. The applied starting materials are readily available through a three-step synthesis, which further contributes to the advantages of this route. In addition, UV-Vis and fluorescent spectra of the obtained CP-anthracenes were recorded.

Recent advances in transition-metal-catalyzed carbene insertion to C-H bonds

C-H functionalization has been emerging as a powerful method to establish carbon-carbon and carbon-heteroatom bonds. Many efforts have been devoted to transition-metal-catalyzed direct transformations of C-H bonds. Metal carbenes generated in situ from transition-metal compounds and diazo or its equivalents are usually applied as the transient reactive intermediates to furnish a catalytic cycle for new C-C and C-X bond formation. Using this strategy compounds from unactivated simple alkanes to complex molecules can be further functionalized or transformed to multi-functionalized compounds. In this area, transition-metal-catalyzed carbene insertion to C-H bonds has been paid continuous attention. Diverse catalyst design strategies, synthetic methods, and potential applications have been developed. This critical review will summarize the advance in transition-metal-catalyzed carbene insertion to C-H bonds dated up to July 2021, by the categories of C-H bonds from aliphatic C(sp³)-H, aryl (aromatic) C(sp²)-H, heteroaryl (heteroaromatic) C(sp²)-H bonds, alkenyl C(sp²)-H, and alkynyl C(sp)-H, as well as asymmetric carbene insertion to C-H bonds, and more coverage will be given to the recent work. Due to the rapid development of the C-H functionalization area, future directions in this topic are also discussed. This review will give the authors an overview of carbene insertion chemistry in C-H functionalization with focus on the catalytic systems and synthetic applications in C-C bond formation.

Elucidating mechanism and reactivity of reaction between donor-acceptor-acceptor 1,3-bisdiazo compound and cinnamyl alcohol catalyzed by Rh2(OAc)4: a DFT study

It is important for diazo compound to take part in organic synthesis. More theoretical and experimental studies focus on mono-diazo compound but fewer on bi-diazo compounds. Here, the mechanism and...

Thermally-Induced Intramolecular [4+2] Cycloaddition of Allylamino- or Allyloxy-Tethered Alkylidenecyclopropanes

A thermally-induced intramolecular [4+2] cycloaddition reaction of allylamino- or allyloxy-tethered alkylidenecyclopropanes has been reported in this paper, giving a new protocol for the rapid construction of polycyclic skeleton molecules in moderate to excellent yields with a broad substrate scope. On the basis of control experiments and DFT calculations, we disclosed that the reaction proceeded through a [4+2] cycloaddition and trace of water assisted 1,3-H shift process to give the target product.

Recent Advances in the Tandem Cyclization/Cycloaddition of Allene Intermediates from Copper-Catalyzed Cross-Coupling of Diazo Compounds with Terminal Alkynes

This short review summarizes the most recent developments (since 2010) in the tandem cyclization/cycloaddition of allene intermediates­, generated from the copper-catalyzed cross-coupling of diazo compounds with terminal alkynes, to afford cyclic compounds.

1 Introduction

2 Cyclization

2.1 Cyclization with Nucleophiles

2.2 Cyclization with Electrophiles

2.3 6π-Electrocyclization

2.4 Other Cyclization

3 Cycloaddition

4 Conclusion

Cu(I)-Catalyzed addition-cycloisomerization difunctionalization reaction of 1,3-enyne-alkylidenecyclopropanes (ACPs)

A copper(i)-catalyzed three-component addition-cycloisomerization difunctionalization reaction of 1,3-enyne-ACPs with Togni I reagent and TMSCN under mild reaction conditions has been developed, affording 3-trifluoroethylcyclopenta[b]naphthalene-4-carbonitrile derivatives. The reaction proceeded through a copper(i)-catalyzed 1,4-addition of conjugated 1,3-enynes via a radical relay process and aromatic cycloisomerization of allene-ACP intermediates.