Hydrogen Borrowing Catalysis with Secondary Alcohols: A New Route for the Generation of β-Branched Carbonyl Compounds
Hydrogen Borrowing Catalysis with Secondary Alcohols: A New Route for the Generation of β-Branched Carbonyl Compounds
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DOI：
10.1021/jacs.6b12840
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发表时间：
2017-02-22
影响因子：
15
通讯作者：
Donohoe, Timothy J.
中科院分区：
文献类型：
--
作者：
Akhtar, Wasim M.;Cheong, Choon Boon;Donohoe, Timothy J.
描述了使用仲醇和Ph*（Me 5 C 6）酮的氢借用反应，以得到β-支化羰基产物（21个实施例）。这种新的C-C键形成方法需要低负载量的[Cp* IrCl 2]（2）、相对低的温度和高达2.0当量的仲醇。观察到底物诱导的非对映选择性，这代表了非对映选择性烯醇化物的第一个实例。借氢烷基化。通过利用Ph* 基团，β-支化产物可以使用逆弗里德尔-克拉夫茨反应直接裂解成相应的酯或酰胺。最后，将该方案应用于香料化合物（+/-）-3-甲基-5-苯基戊醇的合成。
A hydrogen borrowing reaction employing secondary alcohols and Ph* (Me5C6) ketones to give beta-branched carbonyl products is described (21 examples). This new C-C bond forming process requires low loadings of [Cp*IrCl2](2), relatively low temperatures, and up to 2.0 equiv of the secondary alcohol. Substrate induced diastereoselectivity was observed, and this represents the first example of a diastereoselective enolate. hydrogen borrowing alkylation. By utilizing the Ph* group, the beta-branched products could be straightforwardly cleaved to the corresponding esters or amides using a retro-Friedel Crafts reaction. Finally, this protocol was applied to the synthesis of fragrance compound (+/-)-3-methy1-5-phenylpentanol.