1247762-01-1Relevant academic research and scientific papers
Reversed-polarity synthesis of Diaryl Ketones through palladium-catalyzed direct Arylation of 2-Aryl-1,3-dithianes
Yucel, Baris,Walsh, Patrick J.
, p. 3659 - 3667 (2015/01/09)
An umpolung approach to the synthesis of diaryl ketones has been developed based on in situ generation of acyl anion equivalents and their catalytic arylation. This method entails the base-promoted, palladium-catalyzed direct C-H arylation of 2- aryl-1,3-dithianes with aryl bromides. Use of MNACHTUNGTRENUNG( SiMe3)2 (M=Li, Na) base results in reversible deprotonation of the weakly acidic dithiane. In the presence of a Pd(NiXantphos)-based catalyst and aryl bromide, cross-coupling of the metallated 2-aryl- 1,3-dithiane takes place under mild conditions (2 h at rt) with yields as high as 96%. The resulting 2,2- diaryl-1,3-dithianes were converted into diaryl ketones by either molecular iodine, N-bromo succinimide (NBS) or Selectfluor in the presence of water. The dithiane arylation/hydrolysis can be performed in a one-pot procedure to yield a variety of diaryl ketones in good to excellent yields. This method is suitable for rapid and large-scale synthesis of diaryl ketones. A one-pot preparation of anti-cholesterol drug fenofibrate (TriCor) has been achieved on 10.0 mmol scale in 86% yield.
Reversed-polarity synthesis of diaryl ketones through palladium-catalyzed direct arylation of 2-Aryl-1,3-dithianes
Yucel, Baris,Walsh, Patrick J.
, p. 3659 - 3667 (2015/01/09)
An umpolung approach to the synthesis of diaryl ketones has been developed based on in situ generation of acyl anion equivalents and their catalytic arylation. This method entails the base-promoted, palladium-catalyzed direct C-H arylation of 2- aryl-1,3-dithianes with aryl bromides. Use of ( SiMe3)2 (M=Li, Na) base results in reversible deprotonation of the weakly acidic dithiane. In the presence of a Pd(NiXantphos)-based catalyst and aryl bromide, cross-coupling of the metallated 2-aryl- 1,3-dithiane takes place under mild conditions (2 h at rt) with yields as high as 96%. The resulting 2,2- diaryl-1,3-dithianes were converted into diaryl ketones by either molecular iodine, N-bromo succinimide (NBS) or Selectfluor in the presence of water. The dithiane arylation/hydrolysis can be performed in a one-pot procedure to yield a variety of diaryl ketones in good to excellent yields. This method is suitable for rapid and large-scale synthesis of diaryl ketones. A one-pot preparation of anti-cholesterol drug fenofibrate (TriCor) has been achieved on 10.0 mmol scale in 86% yield.
Selective synthetic routes to sterically hindered unsymmetrical diaryl ketones via arylstannanes
Lo Fiego, Marcos J.,Silbestri, Gustavo F.,Chopa, Alicia B.,Lockhart, Maria T.
scheme or table, p. 1707 - 1714 (2011/05/17)
Bulky arylstannanes and bulky aroyl chlorides are good reaction partners for the synthesis of two-, three-, and even four-ortho-substituted benzophenones, in good to excellent isolated yields (47-91%). Three simple and direct routes, with differential advantages, are proposed: (i) a catalyst-free protocol, in o-dichlorobenzene (ODCB) at 180 °C; (ii) a room temperature protocol, using AlCl3 (0.5 equiv), in dichloromethane (DCM); and (iii) a solvent-free, indium-promoted procedure. A radical mechanism is proposed for the indium-mediated reactions.2011 American Chemical Society.
