Catalyticenantioselective chemical reactions involving highly reactive radical species remain largely unexplored. We report herein for the first time a novel enantioselective radical ring-opening cyanation of redox-active oxime esters by dual photoreodox and copper catalysis. This mild protocol shows good functional group tolerance and broad substrate scope, producing a wide range of optically active
Copper-Catalyzed Enantioselective Arylation via Radical-Mediated C–C Bond Cleavage: Synthesis of Chiral ω,ω-Diaryl Alkyl Nitriles
作者:Guo-Qing Cui、Jing-Cheng Dai、Yan Li、Yuan-Bo Li、Duo-Duo Hu、Kang-Jie Bian、Jie Sheng、Xi-Sheng Wang
DOI:10.1021/acs.orglett.1c02725
日期:2021.10.1
The first example of copper-catalyzed ring-opening, enantioselective arylation of cyclic ketoxime esters to access ω,ω-diaryl alkyl nitriles has been developed in high yield (up to 92% yield) with excellent enantioselectivity (up to 91% ee). Side-arm bis(oxazoline) ligand plays a significant role in this asymmetric catalytic transformation, which provides an efficient route to construct diverse chiral
α‐Arylcyclobutanones display unique reactivity that makes them valuable synthetic intermediates and target molecules. We describe the preparation of α‐aryl‐ and α‐heteroarylcyclobutanones through a direct α‐arylation reaction. Problematic fragmentations are avoided by the use of LiOtBu, which promotes a rapid but reversible self‐aldol reaction that slowly releases the enolate required for α‐arylation
α-芳基环丁酮显示出独特的反应活性,使其成为有价值的合成中间体和目标分子。我们描述了通过直接的α-芳基化反应制备α-芳基和α-杂芳基环丁酮的方法。通过使用LiO t Bu避免了有问题的碎片化,LiO t Bu可以促进快速但可逆的自我羟醛反应,从而缓慢释放α芳构化所需的烯醇化物。我们还展示了α-芳基环丁酮的环扩展,该过程在1-甲氧基硫代甲状腺素D的立体选择性合成中得到了突出显示。
Synthesis of Benzodiquinanes via Tandem Palladium-Catalyzed Semipinacol Rearrangement and Direct Arylation
arylation reaction using α-aryl isopropenyl-tert-cyclobutanols has been developed. This reaction gives access to benzodiquinanes in moderate to good yields and tolerates alkyl-, alkoxy-, and halogen-substitutedaryl groups.
2,2-Dimethyl cyclopentanones by acid catalyzed ring expansion of isopropenylcyclobutanols. A short synthesis of (±)-α-cuparenone and (±)-herbertene
作者:Angela M. Bernard、Angelo Frongia、Francesco Secci、Pier P. Piras
DOI:10.1039/b505707h
日期:——
catalyzed ring expansion of isopropenylcyclobutanols; the method allows ready access to the family of sesquiterpenes cuparanes and herbertanes, as demonstrated by the synthesis of (+/-)-alpha-cuparenone and the direct precursor of (+/-)-herbertene.