DFT Calculations on the Mechanism of Transition-Metal-Catalyzed Reaction of Diazo Compounds with Phenols: O–H Insertion versus C–H Insertion

2016 ◽  
Vol 120 (32) ◽  
pp. 6485-6492 ◽  
Author(s):  
Yuan Liu ◽  
Zhoujie Luo ◽  
John Zenghui Zhang ◽  
Fei Xia
Synlett ◽  
2018 ◽  
Vol 30 (05) ◽  
pp. 542-551 ◽  
Author(s):  
Jianbo Wang ◽  
Kang Wang

Transition-metal-catalyzed cross-coupling reactions through metal carbene migratory insertion have emerged as powerful methodology for carbon–carbon bond constructions. Typically, diazo compounds (or in situ generated diazo compounds from N-tosylhydrazones) have been employed as the metal carbene precursors for this type of cross-coupling reactions. Recently, cross-coupling reactions employing non-diazo carbene precursors, such as conjugated ene-yne-ketones, allenyl ketones, alkynes, cyclopropenes, and Cr(0) Fischer carbenes, have been developed. This account will summarize our efforts in the development of transition-metal-catalyzed cross-coupling reactions with these non-diazo carbene precursors.1 Introduction2 Cross-Coupling with Ene-yne-ketones, Allenyl Ketones, and Alkynes3 Cross-Coupling Involving Ring-Opening of Cyclopropenes4 Palladium-Catalyzed Cross-Coupling with Chromium(0) Fischer Carbenes5 Conclusion


2011 ◽  
Vol 83 (3) ◽  
pp. 495-506 ◽  
Author(s):  
Moisés Gulías ◽  
Fernando López ◽  
José L. Mascareñas

We present a compilation of methodologies developed in our laboratories to assemble polycyclic structures containing small- and medium-sized cycles, relying on the use of transition-metal-catalyzed (TMC) cycloadditions. First, we discuss the use of alkylidenecyclopropanes (ACPs) as 3C-atom partners, in particular in their Pd-catalyzed (3 + 2) cycloadditions with alkynes, alkenes, and allenes, reactions that lead to cyclopentane-containing polycyclic products in excellent yields. Then, we present the expansion of this chemistry to a (4 + 3) annulation with conjugated dienes, and to inter- and intramolecular (3 + 2 + 2) cycloadditions using external alkenes as additional 2C-π-systems. These reactions allow the preparation of different types of polycyclic structures containing cycloheptene rings, the topology of the products depending on the use of Pd or Ni catalysts. Finally, we include our more recent discoveries on the development of (4 + 3) and (4 + 2) intramolecular cyclo-additions of allenes and dienes, promoted by Pt and Au catalysts, and discuss mechanistic insights supported by experimental and density functional theory (DFT) calculations. An enantioselective version of the (4 + 2) cycloaddition with phosphoramidite Au(I) catalysts is also presented.


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