Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• Yukiko Karuo Keita Hirata Atsushi Tarui Kazuyuki Sato Kentaro Kawai Masaaki Omote Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan 10.3762/bjoc.20.226 Abstract In this study, we develop the synthesis methods of fluoroalkenes and

• fluorovinyl ethers, which contains a reactive bromine atom, to afford a series of fluoroalkenes and fluoroenynes in moderate to high yields. Keywords: fluoroalkenes; fluoroenynes; multihalogenated vinyl ethers; Suzuki–Miyaura cross-coupling reactions; Sonogashira cross-coupling reactions; Introduction

• Fluoroalkenes are one of the important frameworks for a wide range of industrial fields. For example, they are used as a bioisostere of amide bonds in medicines and agrochemicals, and contribute to the synthesis of peptide medicines that are stable to enzymatic metabolism and possess high lipophilicity [1]. In

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• bond in butenes 1a,b have been presented in the literature. First, Crimmin et al. investigated the reaction of an aluminum(I) complex with fluoroalkenes. Unlike all the presented fluoroolefins, the reaction of the Al(I) complex with (Z)-butene 1b did not allow isolating the intermediate organoaluminum

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• that the biological activities and metabolism properties of some fluoroalkenes are more potent than those of their parent compounds (Figure 2) [23][24][25]. To the best of our knowledge, only one report of highly halogenated aryl fluoroalkenyl ethers similar to 2 has been published [8]. In this report

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

• Savva A. Ponomarev,
• Roman V. Larkovich,
• Alexander S. Aldoshin,
• Andrey A. Tabolin,
• Sema L. Ioffe,
• Jonathan Groß,
• Till Opatz and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27

• fluorinated bicyclic compounds has attracted much attention [40][41][42][43][44][45][46][47]. In this regard, the development of new protocols to relevant monofluorinated bicyclic molecules involving novel versatile fluorine-containing building blocks is of key importance. Fluoroalkenes are recognized to be

Activation of pentafluoropropane isomers at a nanoscopic aluminum chlorofluoride: hydrodefluorination versus dehydrofluorination

• Maëva-Charlotte Kervarec,
• Thomas Braun,
• Mike Ahrens and
• Erhard Kemnitz

Beilstein J. Org. Chem. 2020, 16, 2623–2635, doi:10.3762/bjoc.16.213

• activation of C–F bonds under mild conditions, and hence the addition of the silane HSiEt3 as a hydrogen source [27][48][49]. More recently, ACF was shown to efficiently convert the fluoroalkenes HFO-1234yf (1) and HFO-1234ze (4a) in the presence of the hydrogen source HSiEt3 into the hydrodefluorination or

Synthesis of novel fluorinated building blocks via halofluorination and related reactions

• Attila Márió Remete,
• Tamás T. Novák,
• Melinda Nonn,
• Matti Haukka,
• Ferenc Fülöp and
• Loránd Kiss

Beilstein J. Org. Chem. 2020, 16, 2562–2575, doi:10.3762/bjoc.16.208

• over fluoroalkenes. Note, that fluoroselenation and subsequent oxidative deselenation can be performed efficiently as a one-pot procedure to transform an olefin directly into an allylic fluoride [41][42]. The oxidation of (rac)-30 with MCPBA in CH2Cl2 was ineffective at room temperature and led to

Selective preparation of tetrasubstituted fluoroalkenes by fluorine-directed oxetane ring-opening reactions

• Clément Q. Fontenelle,
• Thibault Thierry,
• Romain Laporte,
• Emmanuel Pfund and
• Thierry Lequeux

Beilstein J. Org. Chem. 2020, 16, 1936–1946, doi:10.3762/bjoc.16.160

• reaction of fluoroalkylidene-oxetanes was directed by the presence of the fluorine atom, enabling a two-step access to tetrasubstituted fluoroalkenes with excellent geometry control. Despite its small van der Waals radii electronic, rather than steric influences of the fluorine atom governed the ring

• olefination or defluorination reactions or a sigmatropic rearrangement, but these approaches are limited and do not allow the synthesis of tetrasubstituted fluoroalkenes with good control of their geometry [18][19][20][21]. In order to develop a selective synthesis for tetrasubstituted fluoroalkenes we

• through an olefination reaction with benzothiazoyl sulfones (Scheme 1) [22]. With these fluoroalkylidene-oxetanes in hands, we studied the selectivity of ring-opening reactions with heteroatom nucleophiles in order to access tetrasubstituted fluoroalkenes. A control of the geometry of these reactions

Computational study of productive and non-productive cycles in fluoroalkene metathesis

• Markéta Rybáčková,
• Jan Hošek,
• Ondřej Šimůnek,
• Viola Kolaříková and
• Jaroslav Kvíčala

Beilstein J. Org. Chem. 2015, 11, 2150–2157, doi:10.3762/bjoc.11.232

• include the initiation steps starting from metathesis precatalysts as Grubbs or Hoveyda–Grubbs 2nd generation precatalysts [15][16][17][18][19][20][21][22]. In contrast to common alkenes, the metathesis of fluoroalkenes has attracted far less attention [23]. Fluorinated modifications have mostly

• concentrated on the side chain of the vinyl group [24][25][26][27] or applications of 2-fluoroalkenes [28][29][30]. As an exception, the reaction of the Grubbs 2nd generation catalyst with 1,1-difluoroethene gave an isolable difluoromethylene-containing ruthenium complex with very poor catalytic activity [31

• alkenes to hydrofluoroalkenes. Moreover, just recently a successful cross metathesis of perfluoroalkenes with vinyl ethers has been published [35]. The reported computations dealing with the metathesis of fluoroalkenes are also extremely scarce. Thus, the mechanism of the cross metathesis of norbornene

New highlights of the syntheses of pyrrolo[1,2-a]quinoxalin-4-ones

• Emilian Georgescu,
• Alina Nicolescu,
• Florentina Georgescu,
• Florina Teodorescu,
• Daniela Marinescu,
• Ana-Maria Macsim and
• Calin Deleanu

Beilstein J. Org. Chem. 2014, 10, 2377–2387, doi:10.3762/bjoc.10.248

• structures have been proposed [7][8]. The correct structure of 2,3-dicarbomethoxy-5-methylpyrrolo[1,2-a]quinoxalin-4-one and the reaction mechanism was proposed by Meth-Cohn [9]. The reactions of 1-substituted 3-(ethoxycarbonylmethyl)benzimidazolium bromides with fluoroalkenes [10] or fluorovinyl tosylates

Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

• Lian-jun Liu,
• Feijun Wang,
• Wenfeng Wang,
• Mei-xin Zhao and
• Min Shi

Beilstein J. Org. Chem. 2011, 7, 555–564, doi:10.3762/bjoc.7.64

• allylic acetates [75][76], carbene-transfer reactions from ethyl diazoacetate [77], formation of conjugated enones and enals [78], regio- and stereoselective synthesis of fluoroalkenes [79], and so on [80][81][82][83][84][85]. However, reports on NHC–Au catalyzed asymmetric reactions are rare [86]. The