Hypervalent λ3-Bromane Strategy for Baeyer−Villiger Oxidation: Selective Transformation of Primary Aliphatic and Aromatic Aldehydes to Formates, Which is Missing in the Classical

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• 作者：Masahito Ochiai ; Akira Yoshimura ; Kazunori Miyamoto ; Satoko Hayashi ; Waro Nakanishi
• 刊名：Journal of the American Chemical Society
• 出版年：2010
• 出版时间：July 14, 2010
• 年：2010
• 卷：132
• 期：27
• 页码：9236-9239
• 全文大小：238K
• 年卷期：v.132,no.27(July 14, 2010)
• ISSN：1520-5126

文摘

A conceptually distinct, modern strategy for Baeyer−Villiger oxidation (BVO) was developed. Our novel method involves initial hydration of water to carbonyl compounds, followed by ligand exchange of hypervalent aryl-λ³-bromane on bromane(III) with the resulting hydrate, yielding a new type of activated Criegee intermediate. The intermediate undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-λ³-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate esters with high selectivity (>95%) under our conditions, while the attempted classical BVO produced only carboxylic acids. This firmly establishes the powerful nature of new methodology for BVO.