Asymmetric Imine Hydroboration Catalyzed by Chiral Diazaphospholenes
作者:Matt R. Adams、Chieh-Hung Tien、Robert McDonald、Alexander W. H. Speed
DOI:10.1002/anie.201709926
日期:2017.12.22
first use of diazaphospholenes as chiral catalysts has been demonstrated with enantioselective iminehydroboration. A chiral diazaphospholene prepared in a simple three‐step synthesis from commercial materials has been shown to achieve the highest enantioselectivity for the hydroboration of alkyl imines with pinacolborane reported to date. Enantiomer ratios of up to 88:12 were obtained with low (2 mol %)
Asymmetric organocatalytic reduction of ketimines with catecholborane employing a N-triflyl phosphoramide Brønsted acid as catalyst
作者:Dieter Enders、Andreas Rembiak、Matthias Seppelt
DOI:10.1016/j.tetlet.2012.11.055
日期:2013.2
The first asymmetric reduction of ketimines with catecholborane employing an enantiopure N-triflyl phosphoramide as the organocatalyst has been developed. Five mole % of the catalyst provides the corresponding secondary amines in very good to almost quantitative yields and good enantioselectivities up to 86:14 e.r. under mild reaction conditions.
4-Cyanobenzenesulfonamides: Amine Synthesis and Protecting Strategy To Compliment the Nosyl Group
作者:Michael A. Schmidt、Ryjul W. Stokes、Merrill L. Davies、Frederick Roberts
DOI:10.1021/acs.joc.7b00608
日期:2017.5.5
amine protecting/activating group within a broader context of amine synthesis. The crystalline sulfonamides could be further elaborated by alkylation and arylation similarly to nitrobenzenesulfonamides. The sulfonamides could withstand conditions that functionalize nitroarenes, such as reductions and vicariousnucleophilicsubstitution reactions.
The influence of the alcohol, as the hydrogen donor, on the efficiency and selectivity of the asymmetrictransferhydrogenation (ATH) of imines is reported for the first time. This discovery not only leads to a highly enantioselective access to N‐aryl and N‐alkyl amines, but also provides new insight into the mechanism of the ATH of imines. Both experimental and computational studies provide support
Graphene-supported NiPd alloy nanoparticles: A novel and highly efficient heterogeneous catalyst system for the reductive amination of aldehydes
作者:Bilal Nişancı、Khadijeh Ganjehyan、Önder Metin、Arif Daştan、Béla Török
DOI:10.1016/j.molcata.2015.08.022
日期:2015.12
and highly efficient heterogeneous catalytic reductiveamination of aldehydes is described. The recently developed graphene supported NiPd alloy nanoparticle (G-NiPd) catalyst using ammonia borane (AB) as a green, stable and safe hydrogen donor was used in a water/methanol mixture (v/v = 2/3) under ambient conditions. The catalytic system was successfully applied in the reductiveamination of various
描述了一种新颖且高效的醛的异相催化还原胺化。使用氨硼烷(AB)作为绿色,稳定和安全的氢供体的最新开发的石墨烯负载NiPd合金纳米颗粒(G-NiPd)催化剂在环境条件下的水/甲醇混合物(v / v = 2/3)中使用。该催化体系已成功应用于各种取代的醛与胺的胺化反应中,并在6小时内以(高达)99%的收率获得了相应的产物。G-NiPd催化剂最多可循环使用五次,而产物收率没有任何重大损失。