(Dynamic) Kinetic Resolution of Enamines/Imines: Enantioselective N‐Heterocyclic Carbene Catalyzed [3+3] Annulation of Bromoenals and Enamines/Imines
作者:Kun‐Quan Chen、Zhong‐Hua Gao、Song Ye
DOI:10.1002/anie.201813047
日期:2019.1.21
The enantioselectiveN‐heterocycliccarbenecatalyzed [3+3] annulation of α‐bromoenals by dynamic kinetic resolution (DKR) of enamines and normal resolution of α,α‐disubstituted imines were developed. The corresponding substituted dihydropyridones were isolated in good yields with excellent diastereo‐ and enantioselectivities, and a high selective factor (up to 83) was realized for the resolution of
A general metal-free route to 1,4-disubstituted and 1,4,5-trisubstituted 1,2,3-triazoles was developed. α-Haloacroleins reacted with organic azides in a DMSO/H2O mixture solvent at room temperature to produce 1,4-disubstituted triazoles (up to 99%) with exclusive regioselectivities. This protocol is convenient and scalable with a broad substrate scope including aliphatic and aromatic azides. The resulting
开发了一种通向1,4-二取代和1,4,5-三取代的1,2,3-三唑的无金属路线。在室温下,α-卤代丙烯醛与有机叠氮化物在DMSO / H 2 O混合溶剂中反应,生成具有区域选择性的1,4-二取代三唑(最高99%)。该协议方便且可扩展,具有广泛的底物范围,包括脂肪族和芳香族叠氮化物。所得三唑在C4位上显示醛基,并证明了其合成用途。还鉴定了一种含有非对映体质子的1,2,3-三唑化合物。
Synthesis of functionalized γ-lactones via a three-component cascade reaction catalyzed by consecutive N-heterocyclic carbene systems
Two consecutive N-heterocyclic carbene (NHC) catalytic systems were combined in a one-pot cascade reaction for the assembly of aromatic aldehydes and 2-haloenals into a structurally complex γ-lactone backbone.
Carbene-Catalyzed Enantioselective Addition of Benzylic Carbon to Unsaturated Acyl Azolium for Rapid Synthesis of Pyrrolo[3,2-<i>c</i>]quinolines
作者:Jilan Wang、Yongjia Li、Jun Sun、Hongling Wang、Zhichao Jin、Yonggui Robin Chi
DOI:10.1021/acscatal.8b02651
日期:2018.10.5
A carbene-catalyzed enantioselective addition of benzylic carbon to α,β-unsaturated acyl azolium intermediate generated via N-heterocyclic carbene catalysis is disclosed. This addition is followed by a stereoselective Mannich reaction and a chemo-selective lactamformation cascade to afford pyrrolo[3,2-c]quinolones as the products with excellent yields and optical purities. This work constitutes an
公开了卡宾催化的苯甲基碳的对映选择性加成到通过N-杂环卡宾催化产生的α,β-不饱和酰基偶氮中间体上。该添加之后是立体选择性曼尼希反应和化学选择性内酰胺形成级联,以提供吡咯并[3,2- c ]喹诺酮作为具有优异收率和光学纯度的产物。这项工作构成有效的不对称苄基sp 3-碳官能化和一步一步快速进入带有四个连续手性中心的多环杂环。
Synthesis of Dihydropyridinone-Fused Indoles and α-Carbolines via N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of Indolin-2-imines and Bromoenals
作者:Liang Yi、Yuyang Zhang、Zhao-Fei Zhang、Dequn Sun、Song Ye
DOI:10.1021/acs.orglett.7b00820
日期:2017.5.5
The N-heterocyclic carbene catalyzed [3 + 3] annulation of indolin-2-imines and bromoenals was developed to give dihydropyridinone-fused indoles in good to high yields, which were transformed to α-carbolines with different 2-subsituents by a process of dehydrogenation, tosylation, and palladium catalyzed C–C or C–N coupling reaction.