Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• in terms of environmental impact, safety and economics. Thus, by the end of the 1990’s, two main phosgene-free large-capacity processes were operative, both based on the incorporation of carbon monoxide (CO) and methanol by transition metal catalysis: one developed by EniChem [57][58], and the other

• necessarily require transition metal catalysis as did the EniChem and Ube processes. Instead, the reaction can be effectively catalyzed by a combination of supported basic ammonium resins and homogeneous alkaline bases [60], thereby demonstrating the potential of transition metal-free catalytic systems for

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• , enantioenriched 3-hydroxyoxindole scaffolds also exist in natural products and have proven to possess promising biological activities. A large number of catalytic asymmetric strategies toward the construction of 3-hydroxyoxindoles based on transition metal catalysis and organocatalysis have been reported in the

• -substituted 3-hydroxyoxindoles and 3-hydroxyoxindole-based further transformations. Keywords: 3-hydroxyoxindoles; oxindoles; organocatalysis; spirooxindoles; transition metal catalysis; Introduction Chiral oxindoles are an important class of compounds, which widely exist in nature and have exhibited diverse

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• have organized this review by the catalyst used, with free carbenes first, followed by Cu, Rh, Au, Pt, and then W-catalyzed reactions. Review Metal-free reactions While transition metal catalysis has seen widespread adoption for carbene and nitrene reactions, it is not necessary for a controlled

• [31]. Metal-catalyzed reactions Copper The earliest example to our knowledge of transition metal catalysis for the formation of bridged rings via C–H bond insertion was Wolff’s use of copper (Scheme 6) [32][33]. Silver was also examined as a possible catalyst, but then a Wolff rearrangement was the

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• –carbene; site-selectivity; Introduction Direct functionalization of inactivated C–H bonds, especially C(sp3)–H bonds, have attracted significant attentions in recent years. The C(sp3)–H bond activation strategies based on radical reactions and transition metal catalysis have been explored, alongside the

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• features two oxidation sensitive veratrole units. Interestingly, a highly chemoselective oxidation was observed and compound 15 was isolated in 60% yield. Trace metal analysis When using transition metal catalysis in the synthesis of compounds designated for application (pharmaceuticals, agrochemicals

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• , functional ligands often play a key role in transition metal catalysis. Accordingly, the bistriazole derivatives could provide promising alternatives to bipyridine ligands because of their powerful nitrogen-centered coordination. In this context, Hao and co-workers have reported bistriazole-based N4

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• ][21][22][23][24] and the synthesis based on transition metal-catalysis [15][27][28][29][30][31][32][33][34][35][36][37]. The main advantage of the radical-based phenanthridine synthesis is easy available and generally cheap starting material (benzotriazole, aminobiphenyl, arylaldehyde, N-(ortho

• -alkylphenanthridine derivatives and 6-phosphorylated analogues, equipped with one or two additional substituents, usually positioned on the phenanthridine positions C1–4 or position C8. Similarly to the radical-based synthesis, a synthetic approach based on transition metal-catalysis also allows the phenanthridine

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• prefunctionalization or lithiation of substrate. However, these methods are not compatible for some activated functional groups in precursor compounds. Over the past several years, we have achieved reactions of C–P bond formation with new and efficient protocols via transition metal-catalysis [11][12][13][14][15][16

Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction

• Marina Rubina,
• William M. Sherrill,
• Alexey Yu. Barkov and
• Michael Rubin

Beilstein J. Org. Chem. 2014, 10, 1536–1548, doi:10.3762/bjoc.10.158

• the isomerization were identified. It was shown that the nature of this isomerization is different from that demonstrated previously using chiral diphosphine ligands. Keywords: asymmetric catalysis; chiral phosphine ligands; cyclopropane; Heck reaction; organophosphorus; transition metal catalysis

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• diversity-oriented syntheses of chromophores [62][63][64][65][66][67][68][69] we have established accesses to chromophores in a one-pot fashion based upon transition metal catalysis as an entry to consecutive multicomponent [70][71] and domino reactions [72]. The highly convergent synthetic approach by

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• ; Chakravarty et al. [24] tested an ansa-bridged BINOL-based PV-cyclodiphosphazane in the asymmetric reduction of acetophenone with BH3 (5–8% ee), while Gade et al. [25] recently introduced BINOL-based PIII-cyclodiphosphazane ligands to transition-metal catalysis (up to 84% ee). We anticipated that by

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• give intermediate vinyl-allenecyclopropane 249, followed by a DVCPR to furnish cycloheptadiene 250. 1,2-Shift and vinyl-carbenoid formation sequences Two major pathways to generate divinylcyclopropanes using transition metal catalysis have been developed. Uemura and coworkers [204] were the first to

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

An investigation of the observed, but counter-intuitive, stereoselectivity noted during chiral amine synthesis via N-chiral-ketimines

• Thomas C. Nugent,
• Richard Vaughan Williams,
• Andrei Dragan,
• Alejandro Alvarado Méndez and
• Andrei V. Iosub

Beilstein J. Org. Chem. 2013, 9, 2103–2112, doi:10.3762/bjoc.9.247

• transition metal catalysis [5][6][7][8] and as resolving agents [9]. Despite their high demand, the ability to produce structurally diverse chiral amines has not kept pace. Spurred by this shortcoming, innovative and improved chemical methods have been developed over the last fifteen years. Among them

Post-Ugi gold-catalyzed diastereoselective domino cyclization for the synthesis of diversely substituted spiroindolines

• Amit Kumar,
• Dipak D. Vachhani,
• Sachin G. Modha,
• Sunil K. Sharma,
• Virinder S. Parmar and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2013, 9, 2097–2102, doi:10.3762/bjoc.9.246

• materials. Based on this work and our continuous interest in transition metal catalysis [45][46][47][48][49][50][51][52][53][54], multicomponent reactions [55][56][57] and the chemistry of the indole core [58][59][60], we herein report a post-Ugi gold-catalyzed intramolecular domino cyclization sequence for

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• reactions such as nucleophilic substitution of P–X compounds with organometallic reagents, nucleophilic substitution of alkyl halides with phosphorus nucleophiles, and nucleophilic addition to polar unsaturated bonds. Recent advances in transition-metal catalysis have realized catalytic cross-coupling

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• compounds. The formation of C–S bonds can also be accomplished in good to excellent yields by transition-metal catalysis [10][11], mainly using palladium [12], copper [13][14][15][16], nickel [17][18] and iron [19][20] salts. Aryl coupling reactions employing different palladium species as catalysts

Recent advances in direct C–H arylation: Methodology, selectivity and mechanism in oxazole series

• Cécile Verrier,
• Pierrik Lassalas,
• Laure Théveau,
• Guy Quéguiner,
• François Trécourt,
• Francis Marsais and
• Christophe Hoarau

Beilstein J. Org. Chem. 2011, 7, 1584–1601, doi:10.3762/bjoc.7.187

• in this article. Methodologies, selectivity, mechanism and future aspects are presented. Keywords: ate complex; catalytic direct arylation; mechanism; oxazole; selectivity; transition-metal catalysis; Introduction Deprotonative metalation of aromatics is widely used as a powerful method for

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• traditional multistep syntheses. Thus, they can be considered to be economically and ecologically efficient [9][10]. In particular, multicomponent syntheses of heterocycles initiated by transition metal catalysis received increasing attention in the past decade [11]. As a one-pot synthetic methodology, this

• novel concept combines the unique reactivity patterns of transition metal catalysis with fundamental organic reactivity, in a sequential or consecutive fashion. Over the years, we have contributed to this concept through Pd/Cu-catalyzed accesses to enones and ynones and the in situ transformation of

Multicomponent reactions

• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 960–961, doi:10.3762/bjoc.7.107

• lead structures of active agents, catalysts and even novel molecule-based materials. This Thematic Series on multicomponent reactions represents a snapshot of a highly dynamic field and spans a broad range, from recent advances in isonitrile-based MCR to transition metal catalysis in MCR; from peptidic

Highly efficient gold(I)-catalyzed Overman rearrangement in water

• Dong Xing and
• Dan Yang

Beilstein J. Org. Chem. 2011, 7, 781–785, doi:10.3762/bjoc.7.88

• allylic trichloroacetimidates to allylic trichloroacetamides (Overman rearrangement) is a powerful and attractive strategy for the synthesis of allylic amines from readily available allylic alcohols [1][2]. This transformation can be conducted thermally at high temperatures or by transition metal

• catalysis under very mild conditions [3][4][5][6][7]. Asymmetric induction has been achieved with certain types of transition metal catalysts (e.g., palladium complexes) in combination with chiral ancillary ligands [8][9][10][11][12][13]. However, although a large number of late transition metal catalysts

Continuous flow hydrogenation using polysilane-supported palladium/alumina hybrid catalysts

• Hidekazu Oyamada,
• Takeshi Naito and
• Shū Kobayashi

Beilstein J. Org. Chem. 2011, 7, 735–739, doi:10.3762/bjoc.7.83

• and substantially increase production. We also recently reported novel transition metal catalysis involving the immobilization of Pd or Pt onto polysilane supports by the microencapsulation method [12]. The Pd catalyst (Pd/PSi) had high activity with no or very little leaching of Pd, and it could be

Suzuki–Miyaura cross-coupling reaction of 1-aryltriazenes with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene–palladium complex catalyst

• Guangming Nan,
• Fang Ren and
• Meiming Luo

Beilstein J. Org. Chem. 2010, 6, No. 70, doi:10.3762/bjoc.6.70

• , arylsulfonyl chlorides and arenediazonium salts with arylboronic acids that gave biaryls in good to excellent yields [28][31][32]. As part of our ongoing investigations aimed at the development of transition metal catalysis, we report here that the Suzuki–Miyaura cross-couplings of 1-aryltriazenes with

A thermally-induced, tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition approach to carbocyclic spirooxindoles

• Kay M. Brummond and
• Joshua M. Osbourn

Beilstein J. Org. Chem. 2010, 6, No. 33, doi:10.3762/bjoc.6.33

• rearrangement of the propargyl acetate 9a using transition metal catalysis (AuCl3 10 mol %, toluene, 1 h, rt) led to hydrolysis of the allenyl acetate functionality. This densely functionalized alkylidene cyclobutene 10a is postulated to arise via the [2 + 2] cycloaddition reaction between the alkyne and the

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

• simultaneously, an acid-catalyzed ortho-arylation of aniline employing the strong Brønsted acid PhNH3B(C6F5)4•Et2O was developed by Bergman et al. indicating the close relationship between strong Brønsted acid- and transition-metal catalysis [70]. A double ortho-hydroarylation of anilines with styrenes was

• optical active ligands for enantioselective transition-metal catalysis (Scheme 22) [71]. To the best of our knowledge, efficient ortho-benzylations of anilines with benzyl alcohols as alkylating reagents have yet to be described [15]. Catalytic Friedel–Crafts allylations Allylated arenes represent