Several Convenient Methods for the Synthesis of 2-Amido Substituted Furans
作者:Albert Padwa、Kenneth R. Crawford、Paitoon Rashatasakhon、Mickea Rose
DOI:10.1021/jo026757l
日期:2003.4.1
Several new methods for the synthesis of differently substituted 2-amidofurans are described. The thermolysis of furan-2-carbonyl azide results in a Curtius rearrangement and the resulting furanyl isocyanate was trapped with various organometallic reagents. A second method consists of a C-N cross-coupling reaction of a bromo-substituted furan with various amides, carbamates, and lactams. The CuI-catalyzed
The Reaction of Cyclic Carbinol Amides with Triflic Anhydride as a Method to Prepare α-Trifluoromethyl-Sulfonamido Furans
作者:Paitoon Rashatasakhon、Albert Padwa
DOI:10.1021/ol0272388
日期:2003.1.1
[reaction: see text] A novel synthesis of alpha-trifluoromethyl-sulfonamido furans via the reaction of cyclic carbinol amides with triflicanhydride has been developed. The reaction proceeds under very mild conditions with a wide set of representative lactams to provide the alpha-trifluoromethyl-sulfonamido-substituted furan in high yield. Rapid access to a 5-substituted indoline can be achieved by
Highly Stable Porous-Carbon-Coated Ni Catalysts for the Reductive Amination of Levulinic Acid via an Unconventional Pathway
作者:Guang Gao、Peng Sun、Yunqin Li、Fang Wang、Zelun Zhao、Yong Qin、Fuwei Li
DOI:10.1021/acscatal.7b01786
日期:2017.8.4
verification experiments and density functional theory calculations, we determined that our Ni-catalyzed reductiveamination of LA with amines underwent an unconventional pathway via amides as the first intermediate, followed by tandem cyclization, intramolecular dehydration, and hydrogenation to the desired pyrrolidones. This pathway was completely different from the reported imine-intermediated route
生物质及其衍生物催化转化为燃料和化学品需要活性和稳定的催化剂。非贵金属催化剂通常由于在液相反应中金属物质的浸出和烧结而失活。在这项工作中,我们报告了一种通过原子层沉积将碳纳米管(CNF x @ Ni @ CNTs)负载在碳纳米管(CNF x @ Ni @ CNTs)上的简便方法,该催化剂用于将乙酰丙酸(LA)与胺还原胺化为吡咯烷酮。在厚度适中的多孔碳保护下,优化的CNF 30NiNiCNTs催化剂显示出99%的吡咯烷酮收率和高达20次运行的可回收性,而没有Ni纳米粒子的浸出和烧结。在验证实验和密度泛函理论计算的基础上,我们确定了我们的镍催化的胺与胺的LA还原胺化反应通过酰胺作为第一个中间体进行了非常规途径,随后进行串联环化,分子内脱水和加氢成所需的吡咯烷酮。此途径与Pt催化系统中报道的亚胺介导途径完全不同。这项工作为液相反应的活性和稳定多相催化剂的设计以及转换反应路径实现了贵金属的替代提供
Umpolung of Hemiaminals: Titanocene-Catalyzed Dehydroxylative Radical Coupling Reactions with Activated Alkenes
Radical measures: A radicalcouplingreaction, which is proposed to proceed through in situ chlorination of a hydroxy group by Me3SiCl, is used to form quaternary carbon centers with amino groups in α position. The reaction can be scaled up and is used in an efficient six‐step total synthesis of (±)‐9,10‐diepi‐stemoamide (see scheme, Cp=cyclopentadienyl, EWG=electron‐withdrawing group).
Asymmetric Brønsted Acid Catalyzed Nucleophilic Addition to in situ Generated Chiral N-Acyliminium Ions
作者:Magnus Rueping、Boris Nachtsheim
DOI:10.1055/s-0029-1218539
日期:2010.1
A new enantioselective Bronsted acid catalyzed nucleophilic substitution of γ-hydroxylactams with indole is presented. The reaction proceeds via an intermediary N-acyliminium ion and provides disubstituted γ-lactams in good yields and with high enantioselectivities.