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Search for "Friedel–Crafts" in Full Text gives 190 result(s) in Beilstein Journal of Organic Chemistry.

When cyclopropenes meet gold catalysts

  • Frédéric Miege,
  • Christophe Meyer and
  • Janine Cossy

Beilstein J. Org. Chem. 2011, 7, 717–734, doi:10.3762/bjoc.7.82

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  • gold complexes involve intramolecular FriedelCrafts reactions and the addition of carbonyl groups. Intramolecular FriedelCrafts reactions In the context of their studies on the Lewis acid-catalyzed rearrangement of strained three-membered ring hydrocarbons, such as methylenecyclopropanes and
  • with traces of water) should favour the formation of the more stable cyclopropyl cation 23. Afterwards, ring-opening and intramolecular FriedelCrafts reactions should enable the formation of indene 20 or naphthalene 21. With the gold catalyst, the formation of indene 19 indicated that electrophilic
  • activation of the cyclopropene 18 also occurred at C2 to afford, after ring-opening, the gold-stabilized allylic cation 24. However, in contrast to the acid-catalyzed reaction, subsequent intramolecular FriedelCrafts cyclization occurred by nucleophilic attack by the phenyl group (at C2) on the organogold
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Published 30 May 2011

Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

  • Aamer Saeed,
  • Madiha Irfan and
  • Shahid Ameen Samra

Beilstein J. Org. Chem. 2011, 7, 638–647, doi:10.3762/bjoc.7.75

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  • of tetrabutylammonium bromide (TBAB) as a phase-transfer catalyst [23][24][25]. The N-alkylcarbazoles were subsequently subjected to FriedelCrafts acetylation at the active positions of carbazole, viz. 3 and 6, with anhydrous aluminum chloride in dry chloroform [26]. The monomers were purified by
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Published 19 May 2011

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

  • Marcus Baumann,
  • Ian R. Baxendale,
  • Steven V. Ley and
  • Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Graphical Abstract
  • . Alternatively, the dimethyl ethylene amine side chain can be introduced in position 3 via a FriedelCrafts-type acylation. The resulting acid chloride is transformed in situ to the corresponding amide which on reduction with lithium aluminium hydride affords sumatriptan (Scheme 10) [12]. In the standard Fischer
  • introduced via a FriedelCrafts/Mannich-type alkylation starting either from formaldehyde and dimethylamine or 2,2-dimethoxy-N,N-dimethylacetamide (Scheme 45). In a recent study a more straightforward and general copper-catalysed three component coupling leading to imidazopyridines has been reported [69
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Published 18 Apr 2011

Molecular rearrangements of superelectrophiles

  • Douglas A. Klumpp

Beilstein J. Org. Chem. 2011, 7, 346–363, doi:10.3762/bjoc.7.45

Graphical Abstract
  • nucleophiles, such as arenes and alkanes. This has led to the development of several new synthetic transformations leading to the functionalization of alkanes. Moreover, superelectrophiles have been used to prepare a wide variety of functionalized arenes. Many types of FriedelCrafts type reactions have been
  • developed. Among the useful FriedelCrafts reactions, a large number of cyclizations have been developed, including efficient routes to heterocyclic systems [12]. Several reports have also described superelectrophiles participating in concerted reactions, such as the Nazarov cyclization [13]. Because
  • migrations or hydride shifts. Simple FriedelCrafts type reactions and cyclizations will not be covered. Review Ring opening reactions Several types of superelectrophiles are known to undergo ring opening reactions. The ring opening reaction step can be followed by the reaction with a nucleophile. For
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Published 23 Mar 2011

SbCl3-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

  • Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

Graphical Abstract
  • can be prepared by the palladium-catalyzed arylation of aryl(azaaryl)methanes with aryl halides [27], cationic Pd(II)/bipyridine-catalyzed addition of arylboronic acids to arylaldehydes [28], and by FriedelCrafts type catalytic alkylation of aromatic rings with aromatic aldehydes and their imines [29
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Published 31 Jan 2011
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  • the OTMS-group is apparently removed due to the fairly acidic conditions to produce cis-5a. Overall, the described cyclization can be classified as an aldol-type reaction of an enol ether to an acetal, or as a Prins-type reaction. Encouraged by these results, we decided to try a related FriedelCrafts
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Published 09 Jul 2010

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

  • Magnus Rueping and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

Graphical Abstract
  • efficient FriedelCrafts alkylations of arenes and heteroarenes using only catalytic amounts of a Lewis acid has gained much attention over the last decade. The new catalytic approaches described in this review are favoured over classical FriedelCrafts conditions as benzyl-, propargyl- and allyl alcohols
  • , or styrenes, can be used instead of toxic benzyl halides. Additionally, only low catalyst loadings are needed to provide a wide range of products. Following a short introduction about the origin and classical definition of the FriedelCrafts reaction, the review will describe the different
  • environmentally benign substrates which can be applied today as an approach towards greener processes. Additionally, the first diastereoselective and enantioselective FriedelCrafts-type alkylations will be highlighted. Keywords: allyl alcohols; arene; asymmetric FriedelCrafts reaction; benzyl alcohols; Friedel
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Published 20 Jan 2010

A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

  • Marc Debeaux,
  • Kai Brandhorst,
  • Peter G. Jones,
  • Henning Hopf,
  • Jörg Grunenberg,
  • Wolfgang Kowalsky and
  • Hans-Hermann Johannes

Beilstein J. Org. Chem. 2009, 5, No. 31, doi:10.3762/bjoc.5.31

Graphical Abstract
  • internal Friedel-Crafts alkylation provides the spiro compound 11. Alternatively, protonation of 4 at C-5 generates the benzylic cation 17, which by intramolecular electrophilic attack leads to the bicyclo[4.3.1]decane derivative 12. Finally, the formation of 13 is a formal hydrogenation of the starting
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Published 16 Jun 2009

New diarylmethanofullerene derivatives and their properties for organic thin- film solar cells

  • Daisuke Sukeguchi,
  • Surya Prakash Singh,
  • Mamidi Ramesh Reddy,
  • Hideyuki Yoshiyama,
  • Rakesh A. Afre,
  • Yasuhiko Hayashi,
  • Hiroki Inukai,
  • Tetsuo Soga,
  • Shuichi Nakamura,
  • Norio Shibata and
  • Takeshi Toru

Beilstein J. Org. Chem. 2009, 5, No. 7, doi:10.3762/bjoc.5.7

Graphical Abstract
  • heterojunction thin film. Synthesis of diarylmethanofullerene derivatives Diarylmethanofullerene derivatives were synthesized according to the method cited in the literature [26]. Synthetic routes are shown in Scheme 1. Generally, the FriedelCrafts acylation of benzene derivatives 10–14 with acid chlorides 3–9
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Published 24 Feb 2009

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

  • Abdelwareth A. O. Sarhan,
  • Omar F. Mohammed and
  • Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

Graphical Abstract
  • In conclusion, a number of 1,1′-substituted diacylferrocenes 5a–e were synthesized by FriedelCrafts reaction. Their structures were confirmed by spectral analyses and were in satisfactory agreements with those reported in literature. Some new 1,1′-bis(1,3-DTF)Fc’s and Fc-DTFs were made as
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Published 19 Feb 2009

Convenient method for preparing benzyl ethers and esters using 2-benzyloxypyridine

  • Susana S. Lopez and
  • Gregory B. Dudley

Beilstein J. Org. Chem. 2008, 4, No. 44, doi:10.3762/bjoc.4.44

Graphical Abstract
  • trifluorotoluene, but toluene has a lower dipole moment and also is subject to FriedelCrafts benzylation under the reaction conditions [6][22]. Trifluorotoluene (also known as benzotrifluoride or BTF) is recommended as a “green” solvent alternative to dichloromethane [23]. Benzylation reactions of N-Boc-serine 3d
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Published 26 Nov 2008

Diels- Alder reactions using 4,7-dioxygenated indanones as dienophiles for regioselective construction of oxygenated 2,3-dihydrobenz[f]indenone skeleton

  • Natsuno Etomi,
  • Takuya Kumamoto,
  • Waka Nakanishi and
  • Tsutomu Ishikawa

Beilstein J. Org. Chem. 2008, 4, No. 15, doi:10.3762/bjoc.4.15

Graphical Abstract
  • ], regioselective synthesis of 4,8,9-trioxygenated 2,3-dihydrobenz[f]indenone 4 [22] was a key issue, which was achieved via C ring construction with intramolecular Friedel-Crafts reaction of naphthalenepropanoic acid 5 (path A, Scheme 1) [23]. However, the utilization of a stoichiometric amount of expensive silver
  • ). Intramolecular Friedel-Crafts reaction of 2,5-dimethoxybenzenepropanoic acid (15) and the 4-brominated derivative 16 [31], by a procedure modified from the synthesis of 4 [23], afforded the corresponding indanones 17 and 18. Cerium ammonium nitrate (CAN) oxidation [32] of indanone 17 smoothly afforded
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Published 15 May 2008

Transition- metal/Lewis acid free synthesis of acyl benzothiophenes via C-C bond forming reaction

  • Sarbani Pal,
  • Mohammad Ashrafuddin Khan,
  • P. Bindu and
  • P. K. Dubey

Beilstein J. Org. Chem. 2007, 3, No. 35, doi:10.1186/1860-5397-3-35

Graphical Abstract
  • acylation has been reported as a useful alternative to the Friedel-Crafts acylation process and a variety of aromatic and aliphatic carboxylic acids have been employed successfully. Encouraged by these results, we decided to adopt a similar strategy for the acylation of benzothiophene. We anticipated that a
  • . Nevertheless, the present process is certainly superior to the classical Friedel-Crafts acylation technique and other multi step synthesis. Further studies on establishing the regeioselectivity and application of this methodology in organic synthesis are under investigation. Acyl benzothiophenes of
  • an expensive transition metal catalyst along with toxic carbon monoxide gas[13] or unstable diazo compounds,[18] or pyrophoric BuLi,[19][20] or a multistep synthesis of starting material.[14] The simplest and straightforward method for the synthesis of acyl benzothiophenes appeared to be the Friedel
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Preliminary Communication
Published 25 Oct 2007

An efficient synthesis of novel pyrano[2,3-d]- and furopyrano[2,3-d]pyrimidines via indium- catalyzed multi- component domino reaction

  • Dipak Prajapati and
  • Mukut Gohain

Beilstein J. Org. Chem. 2006, 2, No. 11, doi:10.1186/1860-5397-2-11

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  • Mukaiyama Aldol reactions, Friedel-Crafts acylations,[6] Pavarob reactions[7] and Diels-Alder reactions[8] in water. Since the work of Loh,[8] indium halide has also been shown to be an effective Lewis acid catalyst for various reactions in aqueous media. [9][10] However, its use in the hetero Diels-Alder
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Published 13 Jun 2006

Total syntheses of oxygenated brazanquinones via regioselective homologous anionic Fries rearrangement of benzylic O-carbamates

  • Glaucia Barbosa Candido Alves Slana,
  • Mariângela Soares de Azevedo,
  • Rosângela Sabattini Capella Lopes,
  • Cláudio Cerqueira Lopes and
  • Jari Nobrega Cardoso

Beilstein J. Org. Chem. 2006, 2, No. 1, doi:10.1186/1860-5397-2-1

Graphical Abstract
  • Metalation (DoM) strategy, [17] offer a mild and regioselective complement to classical Friedel-Crafts approaches for the rational construction of polysubstituted aromatics, biaryls, and several classes of heterocycles (Figure 1). In 1993, Gawley showed that O-benzylcarbamates in the presence of directed
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Published 21 Feb 2006
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