More Like this

1. Deoxygenative α-alkylation and α-arylation of 1,2-dicarbonyls

   https://doi.org/10.1039/d0sc03118f  

   Jin, Shengfei; Dang, Hang T.; Haug, Graham C.; Nguyen, Viet D.; Arman, Hadi D.; Larionov, Oleg V. (September 2020, Chemical Science)

   null (Ed.)

   Construction of C–C bonds at the α-carbon is a challenging but synthetically indispensable approach to α-branched carbonyl motifs that are widely represented among drugs, natural products, and synthetic intermediates. Here, we describe a simple approach to generation of boron enolates in the absence of strong bases that allows for introduction of both α-alkyl and α-aryl groups in a reaction of readily accessible 1,2-dicarbonyls and organoboranes. Obviation of unselective, strongly basic and nucleophilic reagents permits carrying out the reaction in the presence of electrophiles that intercept the intermediate boron enolates, resulting in two new α-C–C bonds in a tricomponent process. 

   more » « less
2. Imino‐λ ³ ‐iodane and Catalytic Amount of I ₂ ‐Mediated Synthesis of N ‐Allylsulfenamides via [2,3]‐Sigmatropic Rearrangement

   https://doi.org/10.1002/ejoc.202000961  

   Makitalo, Cody_L; Yoshimura, Akira; Rohde, Gregory_T; Mironova, Irina_A; Yusubova, Rosa_Y; Yusubov, Mekhman_S; Zhdankin, Viktor_V; Saito, Akio (October 2020, European Journal of Organic Chemistry)

   A facile metal‐free [2,3]‐sigmatropic rearrangement reaction of allyl sulfides viaN‐sulfilimine intermediates has been developed. Treatment of allyl sulfides with imino‐λ³‐iodanes in the presence of a catalytic amount of elemental iodine allowed the reaction to proceed under mild conditions and gave the correspondingN‐allylsulfenamide compounds in moderate to good yields. SeveralN‐allylsulfenamide structures have been confirmed by single‐crystal X‐ray crystallography. The reaction initially involves the sulfonylimino group transfer reaction between imino‐λ³‐iodane and the sulfur atom, resulting in the formation ofN‐sulfilimine species, followed by [2,3]‐sigmatropic rearrangement to form theN‐allylsulfenamide. 

   more » « less
3. Synthesis of 1,3-Diaryltriazenes and Azo Dyes from Aryl Amines Using N-Nitrososulfonamides

   https://doi.org/10.1055/a-1969-4050  

   Yaghoubi, Mahshid; Baxter, Ryan D. (April 2023, Synlett)

   Abstract New methods for the synthesis of 1,3-diaryltriazenes and azo dyes from aryl amines are reported. Both methods involve the formation of aryl diazonium intermediates via the transnitrosation of aryl amines with N-nitrososulfonamides. Each two-step transformation may be performed in one reaction vessel at room temperature with no precautions taken to exclude air or moisture. Several triazene and azo dye structures are reported here for the first time, demonstrating the utility of operating the two-step reaction sequence under mild conditions. 

   more » « less
4. Fluorocyclization of N ‐Propargyl Carboxamides by λ ³ ‐Iodane Catalysts with Coordinating Substituents

   https://doi.org/10.1002/adsc.202000381  

   Takahashi, Shunsuke; Umakoshi, Yuki; Nakayama, Kaii; Okada, Yohei; Zhdankin, Viktor_V; Yoshimura, Akira; Saito, Akio (June 2020, Advanced Synthesis & Catalysis)

   Abstract Aiming at the enhanced catalytic activity of fluoro‐λ³‐iodane generated from iodoarene precatalyst with Selectfluor and HF⋅pyridine, this study focused on the λ³‐iodanes bearing coordinating substituents. Compared to 4‐iodoanisole as a precatalyst of our previous method,N‐methyl‐2‐iodobenzamide or 2‐iodobenzamide worked well in the fluorocyclization ofN‐propargyl carboxamides to oxazoles. Control experiments suggest the equilibrium mixture of iodane‐amine complexes and cyclic iodane fluorides would be involved in the present catalysis. magnified image 

   more » « less
5. Scalable, Chemoselective Nickel Electrocatalytic Sulfinylation of Aryl Halides with SO ₂

   https://doi.org/10.1002/anie.202208080  

   Lou, Terry Shing‐Bong; Kawamata, Yu; Ewing, Tamara; Correa‐Otero, Guillermo A.; Collins, Michael R.; Baran, Phil S. (August 2022, Angewandte Chemie International Edition)

   Abstract Simple access to aryl sulfinates from aryl iodides and bromides is reported using an inexpensive Ni‐electrocatalytic protocol. The reaction exhibits a broad scope, uses stock solution of simple SO₂as sulfur source, and can be scaled up in batch and recycle flow settings. The limitations of this reaction are clearly shown and put into context by benchmarking with state‐of‐the‐art Pd‐based methods. 

   more » « less