描述了在氢借位催化下使用1°或2°醇对各种酮进行的烷基化。最初的研究集中在环丙酮与更高的1°醇(即大于MeOH)的α-烷基化反应上,导致形成α-支化产物。我们通过寻找其他底物来探索这种化学反应,使我们发现,二邻位取代的芳基酮也是特有的支架,其中Ph ∗(C 6 Me 5)酮是最佳选择。进一步的研究表明,该基序对于与2°醇形成β支链产物的烷基化至关重要,这也为研究非对映选择性和分子内氢借入过程提供了机会。
Although α‐alkylation of ketones with primary alcohols by transition‐metal catalysis is well‐known, the same process with secondaryalcohols is arduous and complicated by self‐condensation. Herein a well‐defined, high‐valence cobalt(III)‐catalyst was applied for successful α‐alkylation of ketones with secondaryalcohols. A wide‐variety of secondaryalcohols, which include cyclic, acyclic, symmetrical
Hydrogen Borrowing Catalysis with Secondary Alcohols: A New Route for the Generation of β-Branched Carbonyl Compounds
作者:Wasim M. Akhtar、Choon Boon Cheong、James R. Frost、Kirsten E. Christensen、Neil G. Stevenson、Timothy J. Donohoe
DOI:10.1021/jacs.6b12840
日期:2017.2.22
hydrogen borrowing reaction employing secondary alcohols and Ph* (Me5C6) ketones to give β-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 firstexample of a diastereoselective
Transition metal free α-C-alkylation of ketones using secondary alcohols
作者:Mubarak B. Dambatta、Joseph Santos、Robert R.A. Bolt、Louis C. Morrill
DOI:10.1016/j.tet.2020.131571
日期:2020.11
A base-mediated α-C-alkylation of ketones with secondaryalcohols has been developed. This transition metal free approach employs KOt-Bu as the base and exhibits a broad scope, allowing a range of commodity aliphatic secondaryalcohols and 1-arylethanols to be employed as alkylating agents. Aryl methyl ketones undergo selective mono-α-C-alkylation in high isolated yields (23 examples, 65% average yield)
已经开发了用仲醇进行的碱介导的酮的α- C-烷基化。这种不含过渡金属的方法采用KO t -Bu作为碱,并且具有广泛的应用范围,允许将多种商品脂族仲醇和1-芳基乙醇用作烷基化剂。芳基甲基酮经历选择性单α -C烷基化在高分离产率(23个实例中,65%平均产率)。
Nickel‐Catalysis Enabling α‐Alkylation of Ketones by Secondary Alcohols
作者:Amreen K Bains、Ayanangshu Biswas、Abhishek Kundu、Debashis Adhikari
DOI:10.1002/adsc.202200522
日期:2022.8.16
The α-alkylation of ketones utilizing a secondary alcohol has been accomplished by an isolable, bench-stable, inexpensive nickel catalyst affording high yields of β,β-disubstituted products. This report contributes a nickel catalyst in the pool of a few scarce examples of base metal discovered for this purpose. The substrate scope can span a wide range including aliphatic, alicyclic, and cyclic secondary
Hydrogen borrowing catalysis using 1° and 2° alcohols: Investigation and scope leading to α and β branched products
作者:James R. Frost、Choon Boon Cheong、Wasim M. Akhtar、Dimitri F.J. Caputo、Kirsten E. Christensen、Neil G. Stevenson、Timothy J. Donohoe
DOI:10.1016/j.tet.2021.132051
日期:2021.4
variety of ketonesusing 1° or 2° alcohols under hydrogen borrowing catalysis is described. Initial research focused on the α-alkylation of cyclopropyl ketones with higher 1° alcohols (i.e. larger than MeOH), leading to the formation of α-branchedproducts. Our search for additional substrates with which to explore this chemistry led us to discover that di-ortho-substituted aryl ketones were also privileged
描述了在氢借位催化下使用1°或2°醇对各种酮进行的烷基化。最初的研究集中在环丙酮与更高的1°醇(即大于MeOH)的α-烷基化反应上,导致形成α-支化产物。我们通过寻找其他底物来探索这种化学反应,使我们发现,二邻位取代的芳基酮也是特有的支架,其中Ph ∗(C 6 Me 5)酮是最佳选择。进一步的研究表明,该基序对于与2°醇形成β支链产物的烷基化至关重要,这也为研究非对映选择性和分子内氢借入过程提供了机会。