B(C6F5)3‐Catalyzed Chemoselective Defunctionalization of Ether‐Containing Primary Alkyl Tosylates with Hydrosilanes. Issue 12 (9th February 2017)

• Record Type: Journal Article
• Authors: Chatterjee, Indranil; Porwal, Digvijay; Oestreich, Martin
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 12(2017)
• Page Start: 3389
• Page End: 3391
• Publication Date: 2017-02-09
• Subjects: alcohols -- boron -- deoxygenation -- reduction -- silanes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201611813
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Catalytic C(sp 3 )−O bond cleavage promoted by B(C6 F5 )3 /Et3 SiH proceeds preferentially with primary tosylates in the presence of primary and secondary silyl ethers and aryl ethers. This reactivity difference enables the chemoselective defunctionalization of several 1, n ‐diols, and the efficiency of the new procedure is highlighted by the selective deoxygenation of the hydroxymethyl group of an orthogonally protected carbohydrate. Tosylates with an adjacent phenyl group are cleaved with anchimeric assistance. Abstract : The weakest link : Hydrosilanes activated by B(C6 F5 )3 are known to cleave ethers as well as silyl ethers. However, more reactive tosylates are cleaved prior to those ethers, which allows for the chemoselective deoxygenation of diols and polyols. Other functional groups such as carboxyl groups are also tolerated. Defunctionalization of phenethyl tosylate motifs proceeds with anchimeric assistance (rearrangement).