Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78 Shomachi, Tokushima 770-8505, Japan.
J Am Chem Soc. 2010 Jul 14;132(27):9236-9. doi: 10.1021/ja104330g.
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-lambda(3)-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-lambda(3)-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.
我们开发了一种概念上独特的、现代的 Baeyer-Villiger 氧化 (BVO) 策略。我们的新方法涉及水对羰基化合物的初始水合作用，然后高价芳基-λ(3)-溴烷在溴烷(III)上与生成的水合物进行配体交换，生成一种新型的活化 Criegee 中间体。由于超亲核性，中间体经历 BV 重排，并通过芳基-λ(3)-溴烷基的易于还原消除，生成酯。这种新颖的策略使得能够选择性地诱导直链伯脂肪族和芳族醛的 BV 重排，这在经典的 BVO 中是不存在的：例如，在我们的条件下，辛醛和苯甲醛以高选择性（>95%）得到重排的甲酸盐酯，而尝试的经典 BVO 仅产生羧酸。这充分证明了新的 BVO 方法的强大性质。
