A series of new modular bifunctional chiral thiourea organocatalysts were synthesized from natural Cinchona alkaloids and amino acids, and their performance in the aza-Henry reaction of nitroalkanes to imines, the Michaeladdition of acetylacetone to nitroolefins and the Michaeladdition of acetone to nitroolefins was investigated. Under the mild conditions, the important building blocks β-nitro amines
Chiral ureas and thioureas supported on polystyrene for enantioselective aza-Henry reactions under solvent-free conditions
作者:Rafael Pedrosa、José M. Andrés、Deisy P. Ávila、Miriam Ceballos、Rodrigo Pindado
DOI:10.1039/c4gc02474e
日期:——
Chiral recoverable supported bifunctional ureas or thioureas promote highly enantioselective aza-Henry reactions under solvent-free conditions.
手性可回收支持的双功能脲或硫脲在无溶剂条件下促进高对映选择性的无溶剂条件下的氮杂-Henry反应。
A Novel Bis-Thiourea Organocatalyst for the Asymmetric Aza-Henry Reaction
作者:Constantinos Rampalakos、William D. Wulff
DOI:10.1002/adsc.200800214
日期:2008.8.4
A novelbis-thiourea BINAM-based catalyst for the asymmetricaza-Henryreaction has been developed. This catalyst promotes the reaction of N-Boc imines with nitroalkanes to afford beta-nitroamines with good yields and high enantioselectivities. This catalyst has the advantage that it can be prepared in a single step from commercially available materials. A model is proposed for the catalyst action
Enantioselective Additions of Stabilized Carbanions to Imines Generated from α-Amido Sulfones By Using Lipophilic Salts of Chiral Tris(1,2-diphenylethylenediamine) Cobalt(III) Trications as Hydrogen Bond Donor Catalysts
作者:Hemant Joshi、Subrata Ghosh、John Gladysz
DOI:10.1055/s-0036-1590502
日期:2017.9
S)-dpen)3]3+ 2Cl–BArf20 – [BArf20 – = B(C6F5)4 –] is similarly applied to additions of nitroalkanes (four examples, 89–93% isolated yields, 79–91% ee). Precautions to exclude air or moisture are unnecessary. The enantiopure salt ∆-[Co((S,S)-dpen)3]3+ 2Cl–BArf – [BArf = B(3,5-C6H3(CF3)2)4] is an effective hydrogen bonddonorcatalyst (10 mol%, r.t., CH2Cl2) for enantioselective additions of dialkyl malonates
作为有机合成中的专题钴的一部分出版 抽象的 对映纯盐∆- [Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f – [BAr f = B(3,5-C 6 H 3(CF 3)2)4 ]是有效的氢键供体催化剂(10 mol%,rt,CH 2 Cl 2),用于在K 2 CO 3(十)存在下,将丙二酸二烷基酯对映选择性地加成自砜[ArCH(SO 2 Ph)NHBoc]生成的Boc衍生的芳亚胺例如91-97%的孤立产量,87-99%ee)。非对映异构体盐Λ-[Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f20 – [BAr f20 – = B(C 6 F 5)4 – ]类似地用于添加硝基烷烃(四个例子,分离产率为89–93%,79 –91%ee)。没有必要排除空气或湿气的预防措施。 对映纯盐∆- [Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f –
作者:Xianxing Jiang、Yifu Zhang、Lipeng Wu、Gen Zhang、Xing Liu、Hailong Zhang、Dan Fu、Rui Wang
DOI:10.1002/adsc.200900413
日期:2009.9
doubly stereocontrolled organocatalytic aza-Henry reaction of nitroalkanes to N-Boc-imines generated in situfrom a variety of substituted α-amidosulfones was investigated for the first time, in general, affording the corresponding products with high to excellent yields (up to 93% yield) and enantioselectivities (up to 98% ee), and satisfactory diastereoselectivies (anti/syn up to 98:2). Furthermore