Efficient method for the oxidation of aldehydes and diols with tert-butylhydroperoxide under transition metal-free conditions
摘要:
An efficient, mild, and simple protocol is presented for the oxidation of aldehydes and diols to carboxylic acids utilizing 70% aq TBHP as oxidant and t-BuOK as additive. The oxidation of aldehydes could be achieved by two methods under aqueous medium. Excellent yields of products were obtained in short reaction times. Notably, the products were isolated by simple filtration technique and do not involve chromatographic separation. These reactions may prove to be valuable alternatives to traditional metal-mediated oxidations. Oxidation does not require any transition metals or organic solvents in reaction, making this protocol green. (c) 2013 Elsevier Ltd. All rights reserved.
Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
作者:Stefan Haubenreisser、Thorsten H. Wöste、Claudio Martínez、Kazuaki Ishihara、Kilian Muñiz
DOI:10.1002/anie.201507180
日期:2016.1.4
Molecular structures of the most prominent chiral non‐racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen‐bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts
The present disclosure relates generally to compounds and pharmaceutical compositions suitable as modulators of hemoglobin, and methods for their use in treating disorders mediated by hemoglobin.
by its addition to aldehydes in the presence of boron trifluoride etherate yielded rather stable β-hydroxyalkylboronates (5). The thermal dehydroxyboronation or the alkaline hydrogen peroxide oxidation of 5 gave the corresponding alkenes (6) or 1,2-alkanediols (7) in high yields. The reaction provides a simple procedure for the olefination or the hydroxymethylation of aldehydes.
用Knochel的(二烷氧基硼烷基)甲基锌试剂(2)和CuCN•2LiCl在THF中原位制备[(Me 2 C)2 O 2 BCH 2 ] Cu(CN)ZnI(3),然后将其添加到乙醛中。三氟化硼醚化物的存在会产生相当稳定的β-羟烷基硼酸酯(5)。热dehydroxyboronation或的碱性过氧化氢的氧化5得到相应的烯烃(6)或1,2-烷二醇(7以高收率)。该反应提供了用于醛的烯化或羟甲基化的简单程序。
Synthesis of Unprotected 2-Arylglycines by Transamination of Arylglyoxylic Acids with 2-(2-Chlorophenyl)glycine
The transamination of α-keto acids with 2-phenylglycine is an effective methodology for directly synthesizing unprotected α-amino acids. However, the synthesis of 2-arylglycines by transamination is problematic because the corresponding products, 2-arylglycines, transaminate the starting arylglyoxylic acids. Herein, we demonstrate the use of commercially available l-2-(2-chlorophenyl)glycine as the
Regioselective Hydroperoxylation of Aziridines and Epoxides Only with Aqueous Hydrogen Peroxide
作者:SK Abu Saleh、Atanu Hazra、Saumen Hajra
DOI:10.1002/adsc.202100858
日期:2022.1.18
commercially available 50% aq. H2O2. This method provides an access to secondary benzylic β-hydroperoxy amines and -alcohols and tertiary 3-hydroperoxy oxindoles. The protocol is also applicable to the less reactive alkyl aziridines. Furthermore, an acid-catalyzed Kornblum-DeLaMare type rearrangement of secondary benzylic hydroperoxide has also been revealed to afford amino- and hydroxyl ketones.
已经使用市售的 50% 水溶液探索了氮丙啶和环氧化物(包括螺环氮丙啶和螺环氧羟吲哚)的催化剂和无有机溶剂区域选择性加氢过氧化。H 2 O 2。该方法提供了获得仲苄基β-氢过氧胺和β-醇和叔3-氢过氧羟吲哚的途径。该协议也适用于反应性较低的烷基氮丙啶。此外,酸催化的 Kornblum-DeLaMare 型仲苯甲基氢过氧化物重排也被揭示可提供氨基酮和羟基酮。