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 %)
BF<sub>3</sub>·Et<sub>2</sub>O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
作者:Zhenli Luo、Yixiao Pan、Zhen Yao、Ji Yang、Xin Zhang、Xintong Liu、Lijin Xu、Qing-Hua Fan
DOI:10.1039/d1gc01468d
日期:——
direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF3·Et2O has been developed. A wide range of primary and secondary amines and diversely substitutedaldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the
New chiral stationary phases for liquid chromatography based on small molecules: Development, enantioresolution evaluation and chiral recognition mechanisms
作者:Ye' Zaw Phyo、Joana Teixeira、Maria Elizabeth Tiritan、Sara Cravo、Andreia Palmeira、Luís Gales、Artur M.S. Silva、Madalena M.M. Pinto、Anake Kijjoa、Carla Fernandes
DOI:10.1002/chir.23142
日期:2020.1
the development of new chiralstationaryphases (CSPs) for liquidchromatography (LC) based on chiral derivatives of xanthones (CDXs). Based on the most promising CDX selectors, 12 new CSPs were successfully prepared starting from suitable functionalized small molecules including xanthone and benzophenone derivatives. The chiral selectors comprising one, two, three, or four chiral moieties were covalently
最近,我们报道了基于氧杂蒽酮(CDXs)的手性衍生物的液相色谱(LC)的新手性固定相(CSP)的开发。基于最有前途的CDX选择器,成功地从合适的功能化小分子(包括one吨酮和二苯甲酮衍生物)制备了12种新的CSP。将包含一个,两个,三个或四个手性部分的手性选择剂共价键合到色谱载体上,并进一步填充到LC不锈钢柱(150×2.1 mm ID)中。使用不同种类的手性化合物通过LC评估了新CSP的对映选择性。在评估新的CSP时观察到了对映体分离某些CDX的特异性。除了,通过使用分子对接方法的计算研究对手性识别机理进行了评估,这与色谱参数相符。X射线分析用于建立手性选择器3D结构。
An efficient catalytic reductive amination: A facile one-pot access to 1,2-dihydropyrrolo[3,4-b]indol-3(4H)-ones by using B(C 6 F 5 ) 3 /NaBH 4
to afford 1,2-dihydropyrrolo[3,4-b]indol-3(4H)-ones. An efficient combination of B(C6F5)3 and NaBH4 was developed for direct reductiveamination of aldehydes. In addition, B(C6F5)3 catalyzed tandem amination–amidation of 3-formyl-indole-2-carboxylic acids with different substituted anilines to afford substituted 1,2-dihydropyrrolo[3,4-b]indol-3(4H)-ones.
开发了B(C 6 F 5)3和NaBH 4的有效组合,用于醛的直接还原胺化。容许多种官能团,例如酯,硝基,腈,卤素,烯烃,杂环。而且,酸敏感性保护基如TBDMS和TBDPS不受影响。另外,本方法扩展到3-甲酰基-吲哚-2-羧酸与取代的苯胺的串联胺化反应,得到1,2-二氢吡咯并[3,4-b]吲哚-3(4H)- 。 开发了B(C 6 F 5)3和NaBH 4的有效组合,用于醛的直接还原胺化。另外,B(C 6 F 5)3催化3-甲酰基-吲哚-2-羧酸与不同取代的苯胺的串联胺化反应,得到取代的1,2-二氢吡咯并[3,4-b]吲哚-3( 4 H)-一。
Iron triflate catalyzed reductive amination of aldehydes using sodium borohydride
An efficient and convenient procedure for the reductive amination of aldehydes using NaBH4 in the presence of catalytic amount of Fe(OTf)3 is described.