Iridium-Catalyzed <i>ortho</i>-C(sp<sup>2</sup>)–H Amidation of Benzaldehydes with Organic Azides
作者:Delong Mu、Xinmou Wang、Gong Chen、Gang He
DOI:10.1021/acs.joc.7b00531
日期:2017.4.21
ortho-C(sp2)–H amidation reaction of benzaldehydes with organic azides has been developed. A catalytic amount of 3,5-di(trifluoromethyl)aniline was used to promote the Ir-catalyzed directed C–H amination reaction through a transient aldimine intermediate. This reaction tolerates a broad scope of benzaldehyde substrates and works well with a range of aryl- and alkylsulfonyl azides.
Intramolecular hydrogen-bonding-assisted phosphine-catalysed [3 + 2] cyclisation of ynones with <i>o</i>-hydroxy/amino benzaldehydes
作者:Zhi-Xiong Deng、Zhen-Zhen Xie、Yu Zheng、Jun-An Xiao、Rui-Jia Wang、Hao-Yue Xiang、Hua Yang
DOI:10.1039/c9ob00056a
日期:——
tetrahydrofuran derivatives was developed via a phosphine-catalysed [3 + 2] cyclization reaction of aromatic aldehydes with 4-phenylbut-3-yn-2-one. This is the first example of intermolecularcyclization of ynones with benzaldehydes, which essentially benefited from the intramolecular hydrogen bonding. This new protocol features a broad substrate scope, mild reaction conditions, operational simplicity and easy scale-up
A direct diastereoselective synthetic approach to useful cyclopropane α-amino acid was established via base-promoted [4 + 2] annulations between o-aminobenzaldehydes and alkyl 2-aroyl-1-chlorocyclopropanecarboxylates. The annulation reaction proceeded quickly under mildly basic conditions, affording α-aminocyclopropanecarboxylic acid derivatives in moderate to excellent yields with high diastereoselectivities
Synthesis of 1,2-Dihydroquinolines via Hydrazine-Catalyzed Ring-Closing Carbonyl-Olefin Metathesis
作者:Yunfei Zhang、Jae Hun Sim、Samantha N. MacMillan、Tristan H. Lambert
DOI:10.1021/acs.orglett.0c02116
日期:2020.8.7
The synthesis of 1,2-dihydroquinolines by the hydrazine-catalyzed ring-closing carbonyl-olefin metathesis (RCCOM) of N-prenylated 2-aminobenzaldehydes is reported. Substrates with a variety of substitution patterns are shown. With an acid-labile protecting group on the nitrogen atom, in situ deprotection and autoxidation furnish quinoline. In comparison with related oxygen-containing substrates, the
Transition-Metal-Free Decarboxylative Propargylic Substitution/Cyclization with either Azolium Enolates or Acyl Anions
作者:Shenci Lu、Jun-Yang Ong、Si Bei Poh、Terence Tsang、Yu Zhao
DOI:10.1002/anie.201801340
日期:2018.5.14
unprecedented transition‐metal‐free propargylic substitution reaction with either azoliumenolates or acyl anions, which are generated from aldehydes under N‐heterocyclic carbene catalysis. This new catalytic activation operates on readily available cyclic propargylic carbamates through decarboxylation, and generates reactive allene intermediates that can undergo divergent cyclization pathways to deliver