Novel fragmentation of 3-lithio-3,6-dihydro-1,2-oxazines: Synthesis of 2,5-dihydro-2-furanylamines
摘要:
N-Cbz or N-Boc protected 3,6-dihydro-1,2-oxazines 1 on treatment with LDA at -78-degrees-C undergo a novel rearrangement to provide synthetically useful N-Cbz or N-Boc protected dihydro-2-furanylamines 2.
Oxidative cycloaddition of hydroxamic acids with dienes or guaiacols mediated by iodine(III) reagents
作者:Hisato Shimizu、Akira Yoshimura、Keiichi Noguchi、Victor N Nemykin、Viktor V Zhdankin、Akio Saito
DOI:10.3762/bjoc.14.39
日期:——
[Bis(trifluoroacetoxy)iodo]benzene (BTI) and (diacetoxyiodo)benzene (DIB) efficiently promote the formation of acylnitroso species from hydroxamic acids in the presence of various dienes to give the corresponding hetero-Diels-Alder (HDA) adducts in moderate to high yields. The present method could be applied to the HDA reactions of acylnitroso species with o-benzoquinones generated by the oxidative dearomatization
Hetero Diels-Alder Reaction and Ene Reaction of Acylnitroso Species in situ Generated by Hypoiodite Catalysis
作者:Saki Uraoka、Ikumi Shinohara、Hisato Shimizu、Keiichi Noguchi、Akira Yoshimura、Viktor V. Zhdankin、Akio Saito
DOI:10.1002/ejoc.201801340
日期:2018.12.6
Firstexample of hypoiodite‐catalyzed oxidation for the in situ generation of acylnitroso species, which can be used in hetero Diels–Alder reactions with dienes and in enereactions with alkenes.
Copper(II)-Catalyzed Room Temperature Aerobic Oxidation of Hydroxamic Acids and Hydrazides to Acyl-Nitroso and Azo Intermediates, and Their Diels–Alder Trapping
作者:Duangduan Chaiyaveij、Leah Cleary、Andrei S. Batsanov、Todd B. Marder、Kenneth J. Shea、Andrew Whiting
DOI:10.1021/ol201188d
日期:2011.7.1
2-ethyl-2-oxazoline ligand, is an effective catalyst for the room temperature, aerobicoxidation of hydroxamic acids and hydrazides, to acyl-nitroso and azo dienophiles respectively, which are efficiently trapped in situ via both inter- and intramolecular hetero-Diels–Alder reactions with dienes. Both inter- and intramolecular variants of the Diels–Alder reaction are suitable under the reaction conditions using a variety
Mechanistic Insights into Transition Metal-Catalysed Oxidation of a Hydroxamic Acid within situ Diels–Alder Trapping of the Acyl Nitroso Derivative
作者:Judith A. K. Howard、Gennadiy Ilyashenko、Hazel A. Sparkes、Andrew Whiting、Allen R. Wright
DOI:10.1002/adsc.200700568
日期:2008.4.7
New insights into the mechanism for the transition metal-mediated oxidation of hydroxamicacids to give intermediate acylnitroso species, with subsequent hetero-Diels–Alder trapping are presented. The activation of triphenylphosphine-ligated ruthenium-salen complexes is examined, and evidence is presented for the ruthenium-oxo species which are involved in the oxidative process of the hydroxamic acid