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1. The Thermal Rearrangement of an NHC‐Ligated 3‐Benzoborepin to an NHC‐Boranorcaradiene

   https://doi.org/10.1002/ange.201912234  

   Shimoi, Masaki; Kevlishvili, Ilia; Watanabe, Takashi; Maeda, Katsuhiro; Geib, Steven J.; Curran, Dennis P.; Liu, Peng; Taniguchi, Tsuyoshi (November 2019, Angewandte Chemie)

   Abstract An N‐heterocyclic‐carbene‐ligated 3‐benzoborepin with a bridged structure has been synthesized by double radicaltrans‐hydroboration of benzo[3,4]cycloundec‐3‐ene‐1,5‐diyne with an N‐heterocyclic carbene borane. The thermal reaction of the NHC‐ligated borepin at 150 °C gives an isolable NHC‐boranorcaradiene. Experiments and density functional theory calculations support a mechanism whereby the borepin initially rearranges to a boranorcaradiene by a thermal 6π‐electrocyclic reaction. This is followed by 1,5‐boron shift to give a rearranged boranorcaradiene. This shift occurs with stereoinversion at boron through a transition state with open‐shell diradical character. This is the first example of the isolation of a boranorcaradiene from a thermal reaction of a borepin. 

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2. Palladium-NHC (NHC = N-heterocyclic Carbene)-Catalyzed Suzuki–Miyaura Cross-Coupling of Alkyl Amides

   https://doi.org/10.1021/acscatal.1c05738  

   Wang, Chang-An; Rahman, Md. Mahbubur; Bisz, Elwira; Dziuk, Błażej; Szostak, Roman; Szostak, Michal (February 2022, ACS Catalysis)
3. Hydration reactions catalyzed by transition metal–NHC (NHC = N-heterocyclic carbene) complexes

   https://doi.org/10.1016/j.ccr.2023.215110  

   Gao, Pengcheng; Szostak, Michal (June 2023, Coordination Chemistry Reviews)
4. Suzuki–Miyaura Cross-Coupling of Amides Using Well-Defined, Air- and Moisture-Stable Nickel/NHC (NHC = N-Heterocyclic Carbene) Complexes

   https://doi.org/10.3390/catal10040372  

   Buchspies, Jonathan; Rahman, Md. Mahbubur; Szostak, Michal (April 2020, Catalysts)

   In this Special Issue on N-Heterocyclic Carbenes and Their Complexes in Catalysis, we report the first example of Suzuki–Miyaura cross-coupling of amides catalyzed by well-defined, air- and moisture-stable nickel/NHC (NHC = N-heterocyclic carbene) complexes. The selective amide bond N–C(O) activation is achieved by half-sandwich, cyclopentadienyl [CpNi(NHC)Cl] complexes. The following order of reactivity of NHC ligands has been found: IPr > IMes > IPaul ≈ IPr*. Both the neutral and the cationic complexes are efficient catalysts for the Suzuki–Miyaura cross-coupling of amides. Kinetic studies demonstrate that the reactions are complete in < 1 h at 80 °C. Complete selectivity for the cleavage of exocyclic N-acyl bond has been observed under the experimental conditions. Given the utility of nickel catalysis in activating unreactive bonds, we believe that well-defined and bench-stable [CpNi(NHC)Cl] complexes will find broad application in amide bond and related cross-couplings of bench-stable acyl-electrophiles. 

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5. [(NHC)Pd(OAc) ₂ ]: Highly Active Carboxylate Pd(II)–NHC (NHC = N-Heterocyclic Carbene) Precatalysts for Suzuki–Miyaura and Buchwald–Hartwig Cross-Coupling of Amides by N–C(O) Activation

   https://doi.org/10.1021/acs.joc.4c00103  

   Zhu, Yawei; Yang, Shiyi; Zhou, Tongliang; Szostak, Michal (July 2024, The Journal of Organic Chemistry)