A highly enantioselective catalytic Strecker reaction of cyclic (Z)-aldimines
作者:You-Dong Shao、Shi-Kai Tian
DOI:10.1039/c2cc31001e
日期:——
A range of 3H-indoles and 2H-benzo[b][1,4]thiazines smoothly undergo asymmetric Strecker reaction with ethyl cyanoformate in the presence of a Cinchona alkaloid-based thiourea catalyst at 10 °C to give structurally diverse nitrogen-containing heterocycles in good to excellent yields and with excellent ee.
A Brønsted acid catalyzed highly diastereoselective three‐component cascade reaction of 3H‐indoles, oxazol‐5‐(4H)ones and water is reported. The reaction proceeds under mild conditions with broad substrate scope to give the desired products in high yields.
Benzoicacidcatalysts bearing two amide groups that increase the Brønsted acidity of the carboxylic acid moiety by internalhydrogen‐bonding interactions were designed as a novel class of carboxylic acidcatalysts for the Friedel–Craftsreaction of indoles with β‐nitrostyrenes and 3,3‐disubstituted 3H‐indoles to obtain the corresponding Friedel–Crafts adducts in high yields. The internalhydrogen‐bonding
带有两个酰胺基团的苯甲酸催化剂通过内部氢键相互作用增加了羧酸部分的布朗斯台德酸度,被设计为一类新型的羧酸催化剂,用于吲哚与β-硝基苯乙烯和3,3-的Friedel-Crafts反应。双取代的3 H吲哚,以高收率获得相应的Friedel-Crafts加合物。与内部氢键结合的苯甲酸催化剂相比,苯胺酸具有较高的布朗斯台德酸度,后者基于DMSO中通过紫外分光光度滴定法测得的p K a得出。
Facile Construction of Pyrrolo[1,2-a]indolenine Scaffold via Diastereoselective [3+2] Annulation of Donor–Acceptor Cyclopropane with Indolenine
as part of the Special Topic Modern Cyclization Strategies in Synthesis Abstract A novel synthetic protocol for the assembly of pyrrolo[1,2-a]indolenine has been developed through a highly diastereoselective [3+2] annulation of 1,1-cyclopropanediesters with indolenines in the presence of catalytic Yb(OTf)3. This new strategy allows a facile construction of the multicyclic system with the flexible variation
作为专题“现代合成中的环化策略”的一部分发布 抽象的 一种新型的合成吡咯并[1,2- a ]吲哚烯的合成方案,是通过在催化Yb(OTf)3存在下,将1,1-环丙烷二酯与吲哚烯高度非对映选择性的[3 + 2]环化而开发的。这种新策略可轻松构建多环系统,并在大多数情况下以高收率(> 20:1 dr)具有极高的非对映选择性(最高86%)取代基上的灵活变化。 一种新型的合成吡咯并[1,2- a ]吲哚烯的合成方案,是通过在催化Yb(OTf)3存在下,将1,1-环丙烷二酯与吲哚烯高度非对映选择性的[3 + 2]环化而开发的。这种新策略可轻松构建多环系统,并在大多数情况下以高收率(> 20:1 dr)具有极高的非对映选择性(最高86%)取代基上的灵活变化。
Catalytic Asymmetric 1,2-Difunctionalization of Indolenines with α-(Benzothiazol-2-ylsulfonyl) Carbonyl Compounds
作者:You-Dong Shao、Dao-Juan Cheng
DOI:10.1002/adsc.201700187
日期:2017.8.7
2-difunctionalization reaction of indolenines with α-(benzothiazol-2-ylsulfonyl) carbonyl compounds was developed. By employing the strategy of Brønsted acid-assisted chiral phosphoric acid catalysis, the Mannich addition/Smiles rearrangement cascade occurred smoothly and provided a new family of optically active 1,2-difunctionalized 2-substituted indolines in good yields and enantioselectivities.