Divergent Reactivity of gem-Difluoro-enolates toward Nitrogen Electrophiles: Unorthodox Nitroso Aldol Reaction for Rapid Synthesis of α-Ketoamides
摘要:
An amination reaction of in situ generated gem-difluoro-enolates has been explored with electrophilic nitrogen sources. While their exposure to azodicarboxylates smoothly produced fluorinated alpha-amino ketones, reaction with nitro-soarenes (nitroso aldol reaction) furnished alpha-ketoamides in very high yields (up to 94%). The reaction is very fast (typically completed within 5 min) and scalable and tolerates various sensitive functional groups. Synthetic utility of this process was highlighted through the production of diverse nitrogen heterocycles and an orexin receptor antagonist.
Copper-Catalyzed Aerobic Oxidative Cross-Dehydrogenative Coupling of Amine and α-Carbonyl Aldehyde: A Practical and Efficient Approach to α-Ketoamides with Wide Substrate Scope
A copper-catalyzedaerobicoxidative cross-dehydrogenative coupling (CDC) of amine with α-carbonyl aldehyde has been developed. Many types of amines are tolerant in this transformation leading to various α-ketoamides compounds. Wide substrate scope, CDC strategy and using air as oxidant make this transformation highly efficient and practical. Molecular oxygen acts not only as the oxidant, but also
Copper-Catalyzed Aerobic Oxidative Coupling of Aryl Acetaldehydes with Anilines Leading to α-Ketoamides
作者:Chun Zhang、Zejun Xu、Liangren Zhang、Ning Jiao
DOI:10.1002/anie.201105285
日期:2011.11.18
reaction provides an efficient route to α‐ketoamides compounds, which are ubiquitous structural units in a number of biologically active compounds. N‐substituted anilines are suitable substrates for this transformation. Two CH bonds as well as one CH and one NH bond are cleaved in this reaction. Molecular oxygen (1 atm) is used as the oxidant and the reaction involves dioxygen activation.
A simple and practical method for α-ketoamide synthesis via a decarboxylative strategy of isocyanates with α-oxocarboxylic acids is described. The reaction proceeds at room temperature under mild conditions without an oxidant or an additive, showing good substrate scope and functional compatibility. Moreover, the applicability of this method was further demonstrated by the synthesis of various bioactive
Photoredox‐Catalyzed Tandem Demethylation of
<i>N</i>
,
<i>N</i>
‐Dimethyl Anilines Followed by Amidation with α‐Keto or Alkynyl Carboxylic Acids
作者:Pritha Das、Hasina Mamataj Begam、Samir Kumar Bhunia、Ranjan Jana
DOI:10.1002/adsc.201900525
日期:2019.9.3
for highly selective monodemethylation of N,N‐dimethyl anilines to generate secondary amines and subsequent coupling with α‐ketocarboxylic acids or alkynyl carboxylic acids to form α‐ketoamides or alkynamides respectively undervisiblelight photoredox catalyst in a single operation. From the deuterium‐labeling experiment, it was probed that demethylation is the slowest step in this tandem process
A simple and convenient method for the synthesis of α-ketoamides by the oxidation of aryl acetamides using potassium superoxide (KO2) as an oxidizingagent is disclosed here. The scope of the developed method is successfully tested with fifteen substrates. In addition, the utility of method has been demonstrated by synthesizing an orexin receptor antagonist, a medicinally interesting compound.