First General Route to Substituted α-Arylamino-α′-chloropropan-2-ones by Oxidation of N-Protected Aminohalohydrins: The Importance of Disrupting Hydrogen Bond Networks
摘要:
通过红外光谱和计算机建模证实,δ-芳香族氨基醇中存在分子内和分子间氢键网络,这抑制了它们氧化成相应的δ-氨基酮。一个简单的方案,包括高区域选择性保护(作为氨基甲酸酯)和随后的 Dess-Martin 高碘烷氧化,可得到接近定量产率的所需 N 保护酮,用碘三甲基硅烷温和处理后,可得到一系列不同官能化的δ-±-芳基氨基-δ′-氯酮。
Synthesis of β-amino alcohols using the tandem reduction and ring-opening reaction of nitroarenes and epoxides
作者:Chongyang Shi、Cheng Ren、Erlei Zhang、Huile Jin、Xiaochun Yu、Shun Wang
DOI:10.1016/j.tet.2016.04.083
日期:2016.7
A high yield one-pot synthesis of β-amino alcohols from nitroarenes and 1,2-epoxides was developed, which utilizes inexpensive iron dust as a reducing agent and NH4Cl as the only additive in a 50% (v/v) ethanol solution. This new efficient synthetic approach tolerates a wide range of functionalities. The mild reaction conditions (e.g., 60 °C), together with the use of low cost and readily available
An efficient method for regioselective ring opening of epoxides by amines under microwave irradiation using Bi(NO<sub>3</sub>)<sub>3</sub>·5H<sub>2</sub>O as a catalyst
作者:Shobha Bansal、Yogendra Kumar、Parveen Pippal、Dipak K. Das、Panchanan Pramanik、Prabal P. Singh
DOI:10.1039/c6nj03701a
日期:——
Bismuth(III)nitrate pentahydrate, a highly efficient environmentally benign catalyst, is used for the nucleophilic ringopening of epichlorohydrin and styrene oxide with aromatic, aliphatic and heteroaromatic amines under solvent free microwave conditions reducing the reaction time drastically to afford the corresponding β-amino alcohols in good to excellent yields with high regioselectivity. The products obtained were
硝酸铋(III)五水合物,一种高效的环境友好型催化剂,用于在无溶剂微波条件下与芳香族,脂肪族和杂芳香族胺一起对环氧氯丙烷和氧化苯乙烯进行亲核开环,从而大大缩短了反应时间,从而提供了相应的β-氨基醇具有良好的收率和优异的选择性,并具有较高的区域选择性。获得的产物通过柱色谱法直接纯化,并通过1 H和13 C NMR,FTIR和质谱进行表征。
Zinc(II) Perchlorate Hexahydrate Catalyzed Opening of Epoxide Ring by Amines: Applications to Synthesis of (<i>RS</i>)/(<i>R</i>)-Propranolols and (<i>RS</i>)/(<i>R</i>)/(<i>S</i>)-Naftopidils
作者:Shivani、Brahmam Pujala、Asit K. Chakraborti
DOI:10.1021/jo062674j
日期:2007.5.1
perchlorate hexahydrate was found to be the best catalyst compared to other metal perchlorates. The counteranion modulated the catalytic property of the various Zn(II) compounds that followed the order Zn(ClO4)2·6H2O ≫ Zn(BF4)2 ∼ Zn(OTf)2 ≫ ZnI2 > ZnBr2 > ZnCl2 > Zn(OAc)2 > Zn(CO3)2 in parallelism with the acidic strength of the corresponding protic acids (except for TfOH). The applicability of the methodology
X‐ray structurally characterized Mo (VI), Fe (III) and Cu (II) complexes of amide‐imine conjugate: (bio)catalytic and histidine recognition studies
作者:Sabyasachi Ta、Milan Ghosh、Noor Salam、Jayanta Das、Manirul Islam、Paula Brandão、Vítor Félix、Jesus Sanmartin、Debasis Das
DOI:10.1002/aoc.5823
日期:2020.10
nzohydrazide (H2LPTASAL), derived from 4‐methyl‐benzoicacid hydrazide (PTA) and 2‐hydroxybenzaldehyde is used to prepare Mo (VI), Cu (II) and Fe (III) complexes. The X‐ray structurally characterized complexes have been explored as catalyst for amine assisted asymmetric ring opening (ARO) of epoxide, carbon‐heteroatom cross‐coupling and ethyl benzene oxidation. In addition, their catecholase like activities
衍生自4-甲基苯甲酸酰肼(PTA)和2的酰胺-亚胺共轭物(E)-N'-((2-羟基苯甲酰基-1-基)亚甲基)-4-甲基苯甲酰肼(H 2 L PTASAL) ‐羟基苯甲醛用于制备Mo(VI),Cu(II)和Fe(III)配合物。X射线的结构表征的配合物已被用作催化剂,用于胺辅助的环氧不对称开环(ARO),碳杂原子交叉偶联和乙苯氧化。另外,已经充分研究了它们的儿茶酚酶样活性。而且,Cu(II)配合物通过荧光光谱法选择性地识别组氨酸。
Zinc Tetrafluoroborate Hydrate as a Mild Catalyst for Epoxide Ring Opening with Amines: Scope and Limitations of Metal Tetrafluoroborates and Applications in the Synthesis of Antihypertensive Drugs (<i>RS</i>)/(<i>R</i>)/(<i>S</i>)-Metoprolols
作者:Brahmam Pujala、Shivani Rana、Asit K. Chakraborti
DOI:10.1021/jo201473f
日期:2011.11.4
reaction at the benzylic carbon of the epoxide ring. A reversal of regioselectivity (91:1–69:31) in favor of the reaction at the terminal carbon of the epoxide ring was observed for reaction with morpholine. The regioselectivity was dependent on the electronic and steric factors of the epoxide and the pKa of the amine and independent of amine nucleophilicity. The role of the metal tetrafluoroborates is
已经研究了金属四氟硼酸盐与胺进行环氧化物开环反应的范围和局限性,并且发现Zn(BF 4)2 · x H 2 O是一种温和而有效的催化剂,在无溶剂条件下于200 ℃提供高收率。 rt具有出色的化学,区域和立体选择性。催化效率依次为Zn(BF 4)2 · x H 2 O≫ Cu(BF 4)2 · x H 2 O> Co(BF 4)2 ·6H 2 O≫ Fe(BF 4)2 ·6H2 O> LiBF 4与环己烯氧化物和Zn(BF 4)2 · x H 2 O≫ Co(BF 4)2 ·6H 2 O≫ Fe(BF 4)2 ·6H 2 O> Cu(BF 4)反应2 · x H 2 O,用于氧化二苯乙烯,但AgBF 4是无效的。对于苯乙烯氧化物与苯胺的反应,四氟硼酸金属具有相当的区域选择性(1:99–7:93),并且在环的苄基碳上具有优先反应。与吗啉反应时,观察到区域选择性的逆转(91:1–69:31),有