- Ritter-type amination of C-H bonds at tertiary carbon centers using iodic acid as an oxidant
-
The Ritter-type amination of a tertiary C-H bond using iodic acid (HIO3) as an oxidant, in the presence of N-hydroxyphthalimide (NHPI) is reported. This operationally simple method is conducted under metal-free conditions, is scalable, and efficiently provides valuable α-tertiary amine derivatives.
- Kiyokawa, Kensuke,Takemoto, Kenta,Minakata, Satoshi
-
-
Read Online
- Hypervalent Iodine(III)-Mediated Decarboxylative Ritter-Type Amination Leading to the Production of α-Tertiary Amine Derivatives
-
α-Tertiary amines (ATAs) are attractive structural motifs that are frequently found in biologically active molecules. Therefore, the development of an efficient method for the synthesis of ATAs represents an important research topic in the field of medicinal chemistry as well as organic chemistry. Although the Ritter reaction is a reliable approach for preparing α-tertiary amine derivatives via intermolecular amination reactions, the typical methods suffer from disadvantages such as harsh reaction conditions and the use of strong acids. Because of this, it has been of limited use in the synthesis of ATAs. We report here on the decarboxylative Ritter-type amination of carboxylic acids bearing an α-quaternary carbon center using a combination of PhI(OAc)2 and molecular iodine (I2) to produce the corresponding α-tertiary amine derivatives. This reaction proceeded at ambient temperature on the benchtop with a fluorescent light. Mechanistic investigations suggest that the reaction proceeds via the formation of an alkyl iodide and a higher oxidation state iodine(III) species as key intermediates. Similarly, a stepwise protocol for the Ritter-type amination of alcohols via the formation of oxalic acid monoalkyl esters was also achieved. The present methods represent a useful tool for the synthesis of ATAs that are difficult to prepare by conventional methods.
- Kiyokawa, Kensuke,Watanabe, Tomoki,Fra, Laura,Kojima, Takumi,Minakata, Satoshi
-
p. 11711 - 11720
(2017/11/27)
-
- Photochemistry of N-acetyl-, N-trifluoroacetyl-, N- mesyl-, and N-tosyldibenzothiophene sulfilimines
-
(Chemical Equation Presented) Time-resolved infrared (TRIR) spectroscopy, product studies, and computational methods were applied to the photolysis of sulfilimines derived from dibenzothiophene that were expected to release acetylnitrene, trifluoroacetylnitrene, mesylnitrene, and tosylnitrene. All three methods provided results for acetylnitrene consistent with literature precedent and analogous experiments with the benzoylnitrene precursor, i.e., that the ground-state multiplicity is singlet. In contrast, product studies clearly indicate triplet reactivity for trifluoroacetylnitrene, though TRIR experiments were more ambiguous. Product studies suggest that these sulfilimines are superior sources for sulfonylnitrenes, which have triplet grounds states, to the corresponding azides, and computational studies shed light on the electronic structure of the nitrenes.
- Desikan, Vasumathi,Liu, Yonglin,Toscano, John P.,Jenks, William S.
-
p. 4398 - 4414
(2008/09/21)
-
- Metal-catalyzed organic photoreactions. Photoreaction of 2-chloroacetophenone derivatives with olefins in the presence of silver trifluoromethanesulfonate
-
UV-irradiation of 2-chloroacetophenones and olefins in the presence of silver triflate affords naphthalenone derivatives with high regio and stereoselectivity and chemical yields. A possible mechanism is proposed.
- Oh,Tamura,Sato
-
p. 9687 - 9694
(2007/10/02)
-