51571-26-7Relevant academic research and scientific papers
Direct C-H α-Arylation of Enones with ArI(O2CR)2 Reagents
Sousa E Silva, Felipe Cesar,Van, Nguyen T.,Wengryniuk, Sarah E.
supporting information, p. 64 - 69 (2020/01/22)
α-Arylation of α,β-unsaturated ketones constitutes a powerful synthetic transformation. It is most commonly achieved via cross-coupling of α-haloenones, but this stepwise strategy requires prefunctionalized substrates and expensive catalysts. Direct enone C-H α-arylation would offer an atom- and step-economical alternative, but such reports are scarce. Herein we report the metal-free direct C-H arylation of enones mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of in situ-generated β-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O2CCF3)2 reagents, which are readily accessed from the parent iodoarenes. The reaction is tolerant of a wide range of substitution patterns, and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic investigations implicate arylation via an umpoled "enolonium" species and show that the presence of a β-pyridinium moiety is critical for the desired C-C bond formation.
C?H Oxygenation Reactions Enabled by Dual Catalysis with Electrogenerated Hypervalent Iodine Species and Ruthenium Complexes
Massignan, Leonardo,Tan, Xuefeng,Meyer, Tjark H.,Kuniyil, Rositha,Messinis, Antonis M.,Ackermann, Lutz
supporting information, p. 3184 - 3189 (2020/01/24)
The catalytic generation of hypervalent iodine(III) reagents by anodic electrooxidation was orchestrated towards an unprecedented electrocatalytic C?H oxygenation of weakly coordinating aromatic amides and ketones. Thus, catalytic quantities of iodoarenes in concert with catalytic amounts of ruthenium(II) complexes set the stage for versatile C?H activations with ample scope and high functional group tolerance. Detailed mechanistic studies by experiment and computation substantiate the role of the iodoarene as the electrochemically relevant species towards C?H oxygenations with electricity as a sustainable oxidant and molecular hydrogen as the sole by-product. para-Selective C?H oxygenations likewise proved viable in the absence of directing groups.
Flow Synthesis of Iodonium Trifluoroacetates through Direct Oxidation of Iodoarenes by Oxone
Soldatova, Natalia S.,Postnikov, Pavel S.,Yusubov, Mekhman S.,Wirth, Thomas
, p. 2081 - 2088 (2019/03/11)
Flow chemistry is considered to be a versatile and complementary methodology for the preparation of valuable organic compounds. We describe a straightforward approach for the synthesis of iodonium trifluoroacetates through the direct oxidation of iodoarenes in a simple flow reactor using an Oxone-filled cartridge. Optimization has been carried out using the Nelder–Mead algorithm. The procedure allows a wide range of iodonium salts to be prepared from simple starting materials.
Surgical Cleavage of Unstrained C(sp3)?C(sp3) Bonds in General Alcohols for Heteroaryl C?H Alkylation and Acylation
Wang, Yaxin,Yang, Le,Liu, Shuai,Huang, Lixia,Liu, Zhong-Quan
supporting information, p. 4568 - 4574 (2019/09/04)
We reported herein a predictable and surgical cleavage of carbon-carbon bond in alcohols. A wide range of 1°, 2° and 3° alcohols including sugars and steroids without ring strain or steric hindrance were all compatible with this system. Also it offered a green and practical strategy for generation of alkyl/acyl radicals using alcohols as the sources. Besides, the features of visible-light-initiation, catalyst and metal free, excellent selectivity and mild conditions make it valuable and attractive. (Figure presented.).
Alternative Strategies with Iodine: Fast Access to Previously Inaccessible Iodine(III) Compounds
Hokamp, Tobias,Mollari, Leonardo,Wilkins, Lewis C.,Melen, Rebecca L.,Wirth, Thomas
supporting information, p. 8306 - 8309 (2018/06/29)
Non-iodinated arenes can be easily and selectively converted into (diacetoxyiodo)arenes in a single step under mild conditions by using iodine triacetates as reagents. The oxidative step is decoupled from the synthesis of hypervalent iodine(III) reagents, which can now be prepared conveniently in a one-pot synthesis for subsequent reactions without prior purification. The chemistry of iodine triacetates was also expanded to heteroatom ligand exchanges to form novel inorganic hypervalent iodine compounds.
Simple direct synthesis of [bis(trifluoroacetoxy)iodo]arenes
Page, T. Keri,Wirth, Thomas
, p. 3153 - 3155 (2008/02/10)
A modified procedure for the direct synthesis of hypervalent [bis(trifluoroacetoxy)iodo]arenes is described. It avoids the use of hazardous reagents with the workup being only an aqueous extraction. Georg Thieme Verlag Stuttgart.
Straightforward syntheses of hypervalent iodine(III) reagents mediated by selectfluor
Ye, Chengfeng,Twamley, Brendan,Shreeve, Jean'ne M.
, p. 3961 - 3964 (2007/10/03)
(Chemical Equation Presented) Use of Selectfluor allows hypervalent iodine(III) species such as aryl iodine(III) difluoride, diacetate, and di(trifluoroacetate) and Koser's salt to be easily prepared. Aryl iodine(III) difluoride and diacetate can be synthesized from the corresponding arene and elemental iodine in one-pot procedures.
Easy preparation of [bis(trifluoroacetoxy)iodo]arenes from iodoarenes, with sodium percarbonate as the oxidant
Kazmierczak, Pawel,Skulski, Lech
, p. 810 - 812 (2007/10/03)
Easy and effective preparations of the nearly pure [bis(trifluoroacetoxy) iodo]arenes, ArI(OCOCF)3, from some iodoarenes, ArI, are reported, using an anhydrous) sodium (percarbonate/(CF3CO)2O/CH 2Cl2 system. The colorless, freshly prepared (ArI(OCOCF)3)2 thus obtained were 98-99% pure (by iodometry).
