Asymmetric Formal [3+2] Cycloaddition Reaction of Isocyanoesters to 2‐Oxobutenoate Esters by a Multifunctional Chiral Silver Catalyst
作者:Jin Song、Chang Guo、Peng‐Hao Chen、Jie Yu、Shi‐Wei Luo、Liu‐Zhu Gong
DOI:10.1002/chem.201100636
日期:2011.7.4
Silver‐standard selectivity! The first highly enantioselective formal [3+2] cycloaddition reaction of isocyanoesters with 2‐oxobutenoate esters catalyzed by a chiralsilver complex proceeded readily under the catalysis of a multifunctional chiralsilver complex in high yields and enantiometric excess (ee) values of up to 98 % (see scheme).
Asymmetric Synthesis of Chiral Oxazolines by Organocatalytic Cyclization of α-Aryl Isocyanoesters with Aldehydes
作者:Liu-Zhu Gong、Meng-Xia Xue、Chang Guo
DOI:10.1055/s-0029-1217549
日期:2009.8
A cinchona alkaloid derivative catalyzed the asymmetric formal [3+2] cycloaddition of α-aryl isocyanoesters with aldehydes, affording highly substituted 2-oxazolines with good stereoselectivities of up to 18:1 dr and 90% ee.
一种金鸡纳生物碱衍生物催化了δ-芳基异氰酸酯与醛的不对称形式[3+2]环加成反应,得到了高度取代的 2-恶唑啉,其立体选择性高达 18:1 dr 和 90% ee。
Selective Formation of 2-Imidazolines and 2-Substituted Oxazoles by Using a Three-Component Reaction
作者:Niels Elders、Eelco Ruijter、Frans J. J. de Kanter、Marinus B. Groen、Romano V. A. Orru
DOI:10.1002/chem.200800271
日期:2008.5.29
Selective formation of 2H-2-imidazolines and 2-substituted oxazoles by using a multicomponent reaction of amines, either aldehydes or ketones, and alpha-acidic isocyano amides or esters is described. By selecting the appropriate solvent, Ag(I) or Cu(I) catalyst, or by employing a weak Bronsted acid, the product formation can be fully controlled and directed quantitatively to the desired heterocyclic
Ag-Catalyzed Asymmetric Interrupted Barton–Zard Reaction Enabling the Enantioselective Dearomatization of 2- and 3-Nitroindoles
作者:Wei-Cheng Yuan、Xin-Meng Chen、Jian-Qiang Zhao、Yan-Ping Zhang、Zhen-Hua Wang、Yong You
DOI:10.1021/acs.orglett.1c04036
日期:2022.1.28
We disclose a Ag-catalyzed asymmetric interrupted Barton–Zard reaction of α-aryl-substituted isocyanoacetates with 2- and 3-nitroindoles, which enables the dearomatization of nitroindoles and hence offers rapid access to an array of optically active tetrahydropyrrolo[3,4-b]indole derivatives bearing three contiguous stereogenic centers, including two tetrasubstituted chiral carbon atoms with pretty
我们公开了 α-芳基取代的异氰基乙酸酯与 2-和 3-硝基吲哚的 Ag 催化不对称间断 Barton-Zard 反应,这使得硝基吲哚脱芳构化成为可能,因此可以快速获得一系列光学活性四氢吡咯并[3,4- b ]吲哚衍生物具有三个连续的立体中心,包括两个四取代的手性碳原子,具有很好的结果(高达 99% 的产率,91:9 dr 和 96% ee)。该协议的合成潜力通过产品的克级反应和多功能转化展示了出来。
<i>Cinchona</i> Alkaloid Squaramide-Catalyzed Asymmetric Ugi-Type Reaction of Isocyanoacetates with C,N-Cyclic Azomethine Imines: Access to Chiral Oxazole-Substituted Tetrahydroisoquinolines
We reported herein an unexpected cinchona alkaloid-derived squaramide-catalyzed asymmetric two-component Ugi-type reaction of α-aryl-substituted isocyanoacetates with C,N-cyclic azomethine imines, which provides concise access to optically active C1-oxazole-substituted tetrahydroisoquinolines in good yields (86-93%) and high enantioselectivities (up to 98% enantiomeric excess) under mild conditions