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

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

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

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• ligands in the field of metal-catalysis. This has spurred the development of new routes toward functionalized phosphines. Some of the most important C–P bond formation strategies were reviewed and organized according to the hybridization of carbon in the newly formed C–P bond. Keywords: cross-coupling

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

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• reaction with the chloride ion released during the initial imine acylation. Finally, a combination between Brønsted acid and metal catalysis, promote the isomerization of V to oxazole 21. It is noteworthy, that the gold catalyst seemed to be essential only for the formation of the gold-acetylide

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

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• the O2-mediated selective oxidation of organic compounds and looking for environmentally safe alternatives to metal catalysis. Keywords: autoxidation; free-radicals; metal-free; molecular oxygen; N-hydroxyphthalimide; Introduction The development of efficient and cheap catalytic systems for the

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

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• /Heck reaction starting from N-acryloylanilides [38]. The use of metal catalysis, especially of palladium, has played a major role in the construction of 3-alkenylindolin-2-ones [38]. Despite significant progress in approaches for the construction of 3-alkenylindolin-2-ones, use of complicated

Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives

• Martina Bonsignore,
• Maurizio Benaglia,
• Laura Raimondi,
• Manuel Orlandi and
• Giuseppe Celentano

Beilstein J. Org. Chem. 2013, 9, 633–640, doi:10.3762/bjoc.9.71

• nitrogen atom of the imine [24][25][26]. However, we were attracted by a recent work by Arndtsen, who demonstrated that coupling metal catalysis and the ability of amino acids to form hydrogen bonds provides an easy route for inducing both enantioselectivity and selectivity (left picture in Figure 3) [27

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

New enzymatically polymerized copolymers from 4-tert-butylphenol and 4-ferrocenylphenol and their modification and inclusion complexes with β-cyclodextrin

• Adam Mondrzyk,
• Beate Mondrzik,
• Sabrina Gingter and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2118–2123, doi:10.3762/bjoc.8.238

• condensation. Alternative methods include electrochemical polymerization, metal catalysis or treatment with enzymes, which lead to phenyl–phenyl connected polyphenols [2][3][4][5]. In particular, oxidoreductase enzymes have the great advantage of nontoxicity and regioselective phenol–phenol coupling [6][7][8

Organocatalytic cascade aza-Michael/hemiacetal reaction between disubstituted hydrazines and α,β-unsaturated aldehydes: Highly diastereo- and enantioselective synthesis of pyrazolidine derivatives

• Zhi-Cong Geng,
• Jian Chen,
• Ning Li,
• Xiao-Fei Huang,
• Yong Zhang,
• Ya-Wen Zhang and
• Xing-Wang Wang

Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195

• synthesis of pyrazolidine derivatives by Wolfe et al. [33]. In the past decade, the research area of organocatalysis has grown rapidly and become a third brand of catalysis besides the well-established biocatalysis and metal catalysis [34][35][36][37][38][39][40][41][42][43][44]. Particularly

Synthesis of chiral sulfoximine-based thioureas and their application in asymmetric organocatalysis

• Marcus Frings,
• Isabelle Thomé and
• Carsten Bolm

Beilstein J. Org. Chem. 2012, 8, 1443–1451, doi:10.3762/bjoc.8.164

• diastereoselective transformations or as chiral ligands in enantioselective metal catalysis [25][26][27][28][29][30][31][32][33]. With respect to the latter field we have recently demonstrated that various ligands bearing a sulfonimidoyl moiety lead to excellent stereoselectivities in transition metal-catalyzed

• . They involve both metal catalysis [64][65] as well as organocatalysis. In the latter field, chiral phosphoric acids [66][67], bicyclic diamines [68], bifunctional thioureas [69], proline ester salts [70], pyrrolidinyl tetrazoles [71], and a quinine-derived amine [72] were reported to catalyze the

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

Efficient gold(I)/silver(I)-cocatalyzed cascade intermolecular N-Michael addition/intramolecular hydroalkylation of unactivated alkenes with α-ketones

• Ya-Ping Xiao,
• Xin-Yuan Liu and
• Chi-Ming Che

Beilstein J. Org. Chem. 2011, 7, 1100–1107, doi:10.3762/bjoc.7.126

• molecules. Disappointingly, no conversion was observed when (t-Bu)2(o-diphenyl)PAuOTf only was used as the catalyst. Since dual-metal-catalysis is of interest from the perspective of unique reactivity [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], we explored a new cascade reaction involving

Continuous gas/liquid–liquid/liquid flow synthesis of 4-fluoropyrazole derivatives by selective direct fluorination

• Jessica R. Breen,
• Graham Sandford,
• Dmitrii S. Yufit,
• Judith A. K. Howard,
• Jonathan Fray and
• Bhairavi Patel

Beilstein J. Org. Chem. 2011, 7, 1048–1054, doi:10.3762/bjoc.7.120

• formation by base catalysis, by metal catalysis or by fluorination of appropriate pre-formed enol derivatives, such as trimethylsilyl enols or enol acetate derivatives [13][14]. Dicarbonyl systems are, of course, widely used for the construction of heterocyclic ring systems such a pyrimidine, pyridazine and

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