- High Chemoselectivity in the Construction of Aryl Methyl Sulfones via an Unexpected C-S Bond Formation between Sulfonylhydrazides and Dimethyl Phosphite
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A highly chemoselective route to aryl methyl sulfones via an unexpected C S bond formation between sulfonylhydrazides and dimethyl phosphite catalyzed by NaI under mild conditions has been established. This transformation provides an alternative and metal-free pathway to acquire various aryl methyl sulfones in good to excellent yields. Notably, dimethyl phosphite was employed as a stable and readily available alkyl source.
- Liu, Teng,Yu, Shiwen,Shen, Xiang,Li, Yixian,Liu, Jianjun,Huang, Chao,Cheng, Feixiang
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p. 153 - 160
(2021/10/04)
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- Development of Versatile Sulfone Electrophiles for Suzuki-Miyaura Cross-Coupling Reactions
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The development of fluorinated sulfone derivatives as versatile electrophiles for Suzuki-Miyaura cross-coupling reactions is described. Introducing electron-withdrawing groups on the aryl ring of the sulfone facilitates the Pd-catalyzed activation of C-SO2 bonds. Cross-coupling reactions with fluorinated sulfone electrophiles are reported, leading to a variety of multiply arylated products in good yields. The reactivity of this unusual electrophile is benchmarked versus common electrophiles and its use in iterative cross-couplings for concise synthesis of biologically active molecules is described.
- Nambo, Masakazu,Keske, Eric C.,Rygus, Jason P. G.,Yim, Jacky C.-H.,Crudden, Cathleen M.
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p. 1108 - 1112
(2017/08/09)
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- 3,5-Bis(trifluoromethyl)phenyl sulfones in the direct Julia-Kocienski olefination
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3,5-Bis(trifluoromethyl)phenyl (BTFP) sulfones 7 have been employed in the Julia-Kocienski olefination reaction with carbonyl compounds. Sulfones 7 are readily prepared in high yields (64-97%) from commercially available 3,5-bis(trifluoromethyl)thiophenol through an alkylation/oxidation two-step sequence. The stability of metalated BTFP sulfones has been studied and compared with heteroaryl benzothiazol-2-yl (BT), 1-phenyl-1H-tetrazol-5-yl (PT), and 1-tert-butyl-1H-tetrazol-5-yl (TBT) sulfones 9-11 under different reaction conditions. The Julia-Kocienski olefination between alkyl BTFP sulfones 7 and a wide variety of aldehydes affords the corresponding 1,2-disubstituted alkenes and dienes in good yields and stereoselectivities. This one-pot protocol can be performed using KOH at room temperature or the phosphazene bases P2-Et and P4-t-Bu at -78 °C or rt and has been successfully used in a high-yielding and stereoselective synthesis of various methoxylated stilbenes such as trimethylated resveratrol. These new reaction conditions for the Julia-Kocienski olefination reaction have been also studied with BT, PT, and TBT sulfones, giving poorer results. Methylenation of aliphatic and aromatic aldehydes, ketones, and 1,2-dicarbonyl compounds is carried out through the modified Julia olefination using BTFP methyl sulfone 7d to give terminal alkenes and dienes. Mechanistic studies of the olefination reaction between benzyl BTFP sulfone 7a and aromatic aldehydes performed by KOH-induced Smiles rearrangement of stereodefined syn- and anit-β-hydroxyalkyl BTFP sulfones indicate that the stereocontrol of the reaction is determined in the elimination step. 2005 American Chemical Society.
- Alonso, Diego A.,Fuensanta, Monica,Najera, Carmen,Varea, Montserrat
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p. 6404 - 6416
(2007/10/03)
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