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。
Ruthenium-NHC Catalyzed α-Alkylation of Methylene Ketones Provides Branched Products through Borrowing Hydrogen Strategy
The α-alkylation of a broad range of methylene ketones was achieved using a ruthenium(II)-NHC catalyst under borrowing hydrogen conditions. Primary alcohols served as alkylating agents and could be used in a one-to-one stoichiometry with respect to the ketone. The selectivity of the process for methyl over branched ketones enabled a one-pot double alkylation protocol utilizing two different alcohols
Nickel‐Catalyzed Chemodivergent Coupling of Alcohols: Efficient Routes to Access α,α‐Disubstituted Ketones and α‐Substituted Chalcones
作者:Sadhna Bansal、Benudhar Punji
DOI:10.1002/chem.202304082
日期:2024.3.12
The chemodivergent nickel-catalyzed approach provides α,α-disubstituted ketones from aryl-substituted secondary alcohols and benzyl alcohols via the borrowinghydrogen (BH) strategy in the presence of KOtBu, whereas exclusively α-substituted chalcones were accomplished in the presence of mild base K2CO3 through an acceptorless dehydrogenative coupling (ADC) strategy.
化学发散镍催化方法在 KO t Bu 存在下通过借氢 (BH) 策略从芳基取代的仲醇和苯甲醇提供α , α-二取代酮,而仅α-取代查耳酮是在 KO t Bu 存在下完成的。通过无受体脱氢偶联 (ADC) 策略实现弱碱 K 2 CO 3 。
SYNTHESIS OF COMPOUNDS WITH PREDETERMINED CHIRALITY