Copper Complex of Aminoisoborneol Schiff Base Cu
<sub>2</sub>
(SBAIB‐d)
<sub>2</sub>
: An Efficient Catalyst for Direct Catalytic Asymmetric Nitroaldol (Henry) Reaction
new bifunctional coppercomplex of the aminoisoborneolSchiffbase – Cu2(SBAIB‐d)2 – has been developed for the effective directcatalyticasymmetricHenryreaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henryreaction with nitroethane
An easily available N,N′-dioxide/Cu(I) complex has been developed for the catalyticasymmetric nitroaldol (Henry) reaction of aldehydes with nitroethane. Under mild reaction conditions, a series of substituted aromatic, heteroaromatic and α,β-unsaturated aldehydes are transformed to the corresponding anti-β-nitroalcohols in good to excellent yields (up to 99%) with moderate to good dr (up to 16.7:1
已开发出一种易于获得的N,N'-二氧化物/ Cu(I)络合物,用于醛与硝基乙烷的催化不对称硝基醛醇(Henry)反应。下温和的反应条件下,一系列的取代的芳族,杂芳族和α,β -不饱和醛转化为相应的抗-β-硝基醇以良好至优异的产率(高达99%)的中度至良好博士(高达1670: 1 anti / syn)和高ee值(高达97%)。除硝基乙烷外,还使用硝基甲烷和1-硝基丙烷作为亲核试剂,并获得了良好的对映选择性。
Enantioselective Henry (nitroaldol) reaction catalyzed by axially chiral guanidines
作者:Hitoshi Ube、Masahiro Terada
DOI:10.1016/j.bmcl.2009.03.097
日期:2009.7
The enantioselective activation of nitroalkanes was attempted on the basis of the complexation between chiral guanidinium and nitronate through two hydrogen bonds. The proposed enantioselective activation was applied to the diastereo- and enantioselective Henry (nitroaldol) reaction of nitroalkanes with aldehydes using axiallychiral guanidine bases as the catalyst. Optically active nitroaldol products
Binaphthyl-Proline Hybrid Chiral Ligands: Modular Design, Synthesis, and Enantioswitching in Cu(II)-Catalyzed Enantioselective Henry Reactions
作者:Chao Yao、Yaoqi Chen、Chao Wang、Ruize Sun、Haotian Chang、Ruiheng Jiang、Lin Li、Xin Wang、Yue-Ming Li
DOI:10.1021/acs.joc.2c01127
日期:——
Chiral O–N–N tridentate ligands were designed from proline and BINOL. Their design strategy and performance were evaluated using a copper(II)-catalyzed asymmetric Henryreaction as a model. The desired β-nitroalcohols were obtained in up to 94% ee’s. Preliminary results suggested that the stereofacial selection of the reactions was mainly controlled by the chiral diamine moiety derived from proline
Chiral Mn(III)-salalen and -salan complexes derived from (S)-proline have been used as catalysts for the asymmetric Henry (nitro-aldol) reaction. We have also used this methodology for a variety of substrates to afford nitroaldol products in 40-94% yields with 25-92% ee.