More Like this

1. Ligand Reorganization in the Coordination Sphere of a CCC-NHC Pincer Fe Complex and Transient Absorption Spectroscopic Characterization of [( Bu C i C i C Bu ) 2 Fe]I

   https://doi.org/10.1021/acs.organomet.3c00386  

   Mensah, Joshua ; Adiraju, Venkata K. ; Cope, James D. ; Lamb, Robert W. ; Li, Xiao X. ; Donnadieu, Bruno ; Rubtsov, Igor V. ; Webster, Charles Edwin ; Hollis, T. Keith ( February 2024 , Organometallics)

   Monoligated and bis-ligated CCC-NHC pincer Fe complexes with n-butyl substituents have been synthesized by the Zr metalation/transmetalation route. Both the direct metalation/transmetalation and transmetalation from the isolated (BuCiCiCBu)ZrNMe2Cl2, 3, yielded the octahedrally coordinated Fe(III) bis-ligated complex [(BuCiCiCBu)2Fe]Cl, 2a. Transmetalation from in situ and isolated (BuCiCiCBu)ZrCl3, 5, in the presence of excess TMSCl and 1 equiv of the Fe source yielded the monoligated (BuCiCiCBu)FeCl2, 4. Conditions that convert [(BuCiCiCBu)2Fe]+, 2, to (BuCiCiCBu)FeCl2, 4, complex have been found. Characterization included 1H NMR, UV−visible, femtosecond transient absorption spectroscopies, TDDFT computations, and mass spectroscopy along with X-ray crystallographic structure determinations. 

   more » « less
2. Synthesis of N4 ‐Methylcytidine (m 4 C) and N4,N4‐ Dimethylcytidine (m 4 2 C) Modified RNA

   https://doi.org/10.1002/cpz1.248  

   Zheng, Ya Ying ; Mao, Song ; Sheng, Jia ( September 2021 , Current Protocols)
3. Nickel‐Catalyzed C( sp 2 )−C( sp 3 ) Kumada Cross‐Coupling of Aryl Tosylates with Alkyl Grignard Reagents

   https://doi.org/10.1002/adsc.201801586  

   Piontek, Aleksandra ; Ochędzan‐Siodłak, Wioletta ; Bisz, Elwira ; Szostak, Michal ( April 2019 , Advanced Synthesis & Catalysis)

   Aryl tosylates are an attractive class of electrophiles for cross‐coupling reactions due to ease of synthesis, low price, and the employment of C−O electrophiles, however, the reactivity of aryl tosylates is low. Herein, we report the Ni‐catalyzed C(sp²)−C(sp³) Kumada cross‐coupling of aryl tosylates with primary and secondary alkyl Grignard reagents. The method delivers valuable alkyl arenes by cross‐coupling with challenging alkyl organometallics possessing β‐hydrogens that are prone to β‐hydride elimination and homo‐coupling. The reaction is catalyzed by an air‐ and moisture stable‐Ni(II) precatalyst. A broad range of electronically‐varied aryl tosylates, including bis‐tosylates, underwent this transformation, and many examples are suitable at mild room temperature conditions. The combination of Ar−X cross‐coupling with the facile Ar−OH activation/cross‐coupling strategy permits for orthogonal cross‐coupling with challenging alkyl organometallics. Furthermore, we demonstrate that the method operates with TON reaching 2000, which is one of the highest turnovers observed to date in Ni‐catalyzed cross‐couplings.

   magnified image

    

   more » « less
4. Stereoretentive C( sp 3 )–S Cross-Coupling

   https://doi.org/10.1021/jacs.8b11211  

   Zhu, Feng ; Miller, Eric ; Zhang, Shuo-qing ; Yi, Duk ; O’Neill, Sloane ; Hong, Xin ; Walczak, Maciej A. ( December 2018 , Journal of the American Chemical Society)
5. Evidence for a lowest energy 3 MLCT excited state in [Fe(tpy)(CN) 3 ] −

   https://doi.org/10.1039/d1cc01090e  

   Vittardi, Sebastian B. ; Magar, Rajani Thapa ; Schrage, Briana R. ; Ziegler, Christopher J. ; Jakubikova, Elena ; Rack, Jeffrey J. ( May 2021 , Chemical Communications)

   null (Ed.)

   Transient absorption data of [Fe II (tpy)(CN) 3 ] − reveals spectroscopic signatures indicative of 3 MLCT with a ∼10 ps kinetic component. These data are supported by DFT and TD-DFT calculations, which show that excited state ordering is responsive to the number of cyanide ligands on the complex. 

   more » « less