New Highly Asymmetric Henry Reaction Catalyzed by CuII and aC1-Symmetric Aminopyridine Ligand, and Its Application to the Synthesis of Miconazole
作者:Gonzalo Blay、Luis R. Domingo、Victor Hernández-Olmos、José R. Pedro
DOI:10.1002/chem.200800069
日期:2008.5.19
A new catalytic asymmetricHenryreaction has been developed that uses a C(1)-symmetric chiral aminopyridineligand derived from camphor and picolylamine. A variety of aromatic, heteroaromatic, aliphatic, and unsaturated aldehydes react with nitromethane and other nitroalkanes in the presence of DIPEA (1.0 equiv), Cu(OAc)(2)*H(2)O (5 mol %), and an aminopyridineligand (5 mol %) to give the expected
A Highly<i>anti</i>-Selective Asymmetric Henry Reaction Catalyzed by a Chiral Copper Complex: Applications to the Syntheses of (+)-Spisulosine and a Pyrroloisoquinoline Derivative
作者:Kun Xu、Guoyin Lai、Zhenggen Zha、Susu Pan、Huanwen Chen、Zhiyong Wang
DOI:10.1002/chem.201201775
日期:2012.9.24
A highly anti‐selective asymmetricHenryreaction has been developed, affording synthetically versatile β‐nitroalcohols in a predominately anti‐selective manner (mostly above 15:1) and excellent ee values (mostly above 95 %). Moreover, the anti‐selective Henryreaction was carried out in the presence of water for the first time with up to 99 % ee. The catalytic mechanism was proposed based on the detection
Synthesis of <i>C</i><sub>1</sub>-Symmetric Chiral Secondary Diamines and Their Applications in the Asymmetric Copper(II)-Catalyzed Henry (Nitroaldol) Reactions
作者:Yirong Zhou、Junfang Dong、Fanglin Zhang、Yuefa Gong
DOI:10.1021/jo102124d
日期:2011.1.21
A small library of C1-symmetric chiral diamines (L1−L9) was constructed via condensing exo-(−)-bornylamine or (+)-(1S,2S,5R)-menthylamine with various Cbz-protected amino acids. Among them, ligand L1/CuCl2·2H2O complex (2.5 mol %) shows outstanding catalytic efficiency for Henryreaction between a variety of aldehydes and nitroalkanes to afford the expected products in high yields (up to 98%) with
preparation in THF, a heterogeneous mixture developed and centrifugation of the suspension allowed for separation of the precipitate, which contained the active catalyst and which could be stored for at least 1 month without any loss of catalytic performance. The precipitate promoted a nitroaldol (Henry) reaction for a broad range of nitroalkanes and aldehydes under heterogeneous conditions, affording
描述了由 Nd(5)O(O(i)Pr)(13)、基于酰胺的配体和 NaHMDS(六甲基二硅肼钠)组成的异双金属催化剂促进的抗选择性催化不对称硝基醛醇反应的全部细节。酰胺基配体的系统合成和评估导致最佳配体1m的鉴定,这为Nd/Na异质双金属配合物提供了合适的平台。在 THF 中制备催化剂的过程中,形成了一种非均相混合物,悬浮液的离心允许沉淀物分离,其中含有活性催化剂并且可以储存至少 1 个月而不会损失任何催化性能。沉淀促进了多种硝基烷烃和醛在非均相条件下的硝基醛醇 (Henry) 反应,得到相应的 1, 2-硝基烷醇以高度抗选择性(高达 anti/syn = >40/1)和对映选择性方式(高达 98% ee)。电感耦合等离子体 (ICP) 和 X 射线荧光 (XRF) 分析表明,沉淀确实包含钕和钠,高分辨率 ESI TOF MS 光谱法进一步支持了这一点。
Preparation of Nd/Na heterogeneous catalyst from bench-stable and inexpensive Nd salt for an anti-selective catalytic asymmetric nitroaldol reaction
a highly efficient heterogeneouscatalyst for an anti-selective catalytic asymmetric nitroaldol reaction. Nd alkoxide is sensitive to moisture, expensive, and scarce, making it difficult to use the Nd/Na catalyst in large-scale applications. Herein we describe a new protocol that allows for catalyst preparation from bench-stable and inexpensive NdCl3·6H2O with comparable catalytic activity.