Directed aromatic functionalization

• Victor Snieckus

Beilstein J. Org. Chem. 2011, 7, 1215–1218, doi:10.3762/bjoc.7.141

• sp, sp2, and sp3, and –O, –N, and –S bonds are made to the aromatic ring carbon [25]. These strategies rapidly furnish biaryls/heterobiaryls, and condensed complex aromatics/heteroaromatics whose construction by previous generation methods (e.g., diazonium and radical coupling) has been clearly

Cationic gold(I) axially chiral biaryl bisphosphine complex-catalyzed atropselective synthesis of heterobiaryls

• Tetsuro Shibuya,
• Kyosuke Nakamura and
• Ken Tanaka

Beilstein J. Org. Chem. 2011, 7, 944–950, doi:10.3762/bjoc.7.105

• biaryls [5][6][7]. These reports clearly demonstrated the utility of the asymmetric annulation strategy for the atropselective biaryl synthesis [8]. As an alternative asymmetric annulation method for the atropselective biaryl synthesis, we turned our attention to transition-metal catalyzed

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• arylboronic acids is one of the most important and powerful methods for the construction of biaryls and polyaryls due to its compatibility towards a wide range of functional groups on both partners [5][6][7][8][9][10]. The resulting Suzuki products have found numerous applications in the synthesis of natural

• products, pharmaceutical intermediates, pesticides, advanced materials and liquid crystals [8][9][10]. These applications, in turn, have led to the production of biaryls and polyaryls on the industrial scale [11]. The Suzuki reaction is usually performed with homogeneous palladium catalysts in the presence

• reaction times compared to arylboronic acids, probably as a result of strong coordination of the heterocyclic nitrogen with Pd metal. Ortho substituted aryl iodides required slightly longer reaction times to give the corresponding biaryls. The coupling of 4-chloroiodobenzene with phenylboronic acid gave

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

• . Various aryltriazenes were investigated as electrophilic substrates at room temperature to give biaryls in good to excellent yields and showed good chemoselectivity over aryl halides in the reactions. Keywords: 1-aryltriazenes; N-heterocyclic carbene–palladium complex; polymer-supported catalyst

• ; recyclable catalyst; Suzuki–Miyaura reaction; Introduction The unsymmetrical biaryls feature in a diverse range of organic compounds, such as natural products, advanced materials, liquid crystals, ligands and molecules of medicinal interest [1][2][3][4]. The palladium-catalyzed Suzuki–Miyaura cross-coupling

• reaction has evolved as a powerful synthetic tool for the synthesis of unsymmetrical biaryls in both academic laboratories and industry [5][6][7][8]. Most of the reported Suzuki–Miyaura reactions are based on the use of aryl halides and triflates, and recently sulfonates and carboxylates, as the

Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al₂O₃ under inspection

• Franziska Bernhardt,
• Ronald Trotzki,
• Tony Szuppa,
• Achim Stolle and
• Bernd Ondruschka

Beilstein J. Org. Chem. 2010, 6, No. 7, doi:10.3762/bjoc.6.7

• 2 yielding substituted biaryls 3 under ball milling conditions (palladium-catalyzed and SRS-assisted). Representative experimental procedures for the preparation of KF–Al2O3. Characteristics of the base components applied in Suzuki–Miyaura reactions as SRS. Influence of preparation and storage

Chiral amplification in a cyanobiphenyl nematic liquid crystal doped with helicene-like derivatives

• Alberta Ferrarini,
• Silvia Pieraccini,
• Stefano Masiero and
• Gian Piero Spada

Beilstein J. Org. Chem. 2009, 5, No. 50, doi:10.3762/bjoc.5.50

• designed as pseudo-P when the two phenyl rings are arranged in such a way that a clockwise rotation (<90°) of the ring closer to the observer is required to obtain the coplanarity of the two aromatic planes). In most cases, (pseudo-P)-biaryls induce (P)-cholesterics; however, the relationship between

Oxidative cyclization of alkenols with Oxone using a miniflow reactor

• Yoichi M. A. Yamada,
• Kaoru Torii and
• Yasuhiro Uozumi

Beilstein J. Org. Chem. 2009, 5, No. 18, doi:10.3762/bjoc.5.18

• laminar flow interface [16], resulting in the instantaneous production of biaryls (quantitative yield within 4 s of residence time) via a palladium-catalyzed Suzuki-Miyaura reaction under microflow conditions. An additional advantage of micro- and minireactors is the small heat capacity of the micro- and

Synthesis of unsymmetrically substituted biaryls via sequential lithiation of dibromobiaryls using integrated microflow systems

• Aiichiro Nagaki,
• Naofumi Takabayashi,
• Yutaka Tomida and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2009, 5, No. 16, doi:10.3762/bjoc.5.16

• micromixers and four microtube reactors to obtain unsymmetrically substituted biaryl compounds. Keywords: dibromobiaryls; fast mixing; integrated microflow system; selective lithiation; unsymmetrically substituted biaryls; Introduction Unsymmetrical biaryls have received significant research interest

• biaryls [2][3][4][5][6][7][8][9]. Selective monolithiation of dihalobiaryls also seems to be useful for synthesis of unsymmetrically substituted biaryls because the remaining halogen atom can be utilized for further transformations [10][11][12]. However, halogen-lithium exchange reactions of dihalobiaryls

• ][53]. Recently, we reported that selective monolithiation can be achieved by extremely fast 1:1 micromixing of dibromobiaryls and n-butyllithium using microflow systems [54]. The successful results prompted us to perform a study on the synthesis of unsymmetrically substituted biaryls via sequential

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• donor in specific organometallic reactions, such as the chromium-mediated allylation of aldehydes and ketones [54][55] and the palladium-catalyzed reductive homo-coupling of aryl halides to afford the corresponding biaryls [56][57][58][59] illustrate further versatility of the reagent. The fact that

Asymmetric synthesis of biaryl atropisomers by dynamic resolution on condensation of biaryl aldehydes with (−)-ephedrine or a proline- derived diamine

• Ann Bracegirdle,
• Jonathan Clayden and
• Lai Wah Lai

Beilstein J. Org. Chem. 2008, 4, No. 47, doi:10.3762/bjoc.4.47

• % yield. Hydrolysis and reduction of the major diastereoisomeric product of the reaction yields atropisomeric biaryls in >99:1 enantiomeric ratios. Keywords: atropisomer; biaryl; dynamic resolution; ephedrine; imdazolidine; oxazolidine; Introduction Atropisomeric biaryl compounds have proved to be among

• the most successful of all chiral ligands for metal-catalysed asymmetric transformations [1][2]. Many biaryl ligands have been obtained in enantiomerically pure form by means of resolution [3], but there are also a number of important enantioselective methods for the synthesis of biaryls [4][5][6][7

• significantly on conditions of the reaction, and is the result of a complex interplay of kinetic and thermodynamic effects. The best selectivities, of up to 5:1, were obtained on reaction of alkoxy-substituted biaryls with the diamine in a sealed tube, presumably because water plays a role in assisting

A convenient catalyst system for microwave accelerated cross- coupling of a range of aryl boronic acids with aryl chlorides

• Matthew L. Clarke,
• Marcia B. France,
• Jose A. Fuentes,
• Edward J. Milton and
• Geoffrey J. Roff

Beilstein J. Org. Chem. 2007, 3, No. 18, doi:10.1186/1860-5397-3-18

• equivalents of base was heated under standard conditions and then directly analysed by 19F NMR spectroscopy. Neither of the two possible biaryls that could form from the two boronic acids were detected (92% aryl chroride starting material detected). In a separate experiment, under similar conditions, 3-fluoro

• strategies are required. In summary, a readily prepared, air stable Pd pre-catalyst derived from the amine-phosphine ligand, dcpmp has been found to promote Suzuki coupling between activated aryl chlorides and a range of boronic acids under microwave heating conditions. High yields of the desired biaryls can

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

• 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

An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions

• T. Kop-Weiershausen,
• J. Lex,
• J.-M. Neudörfl and
• B. Goldfuss

Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6

• -catalyzed 1,4-additions of ZnEt2 to 2-cyclohexen-1-one, this P-H phosphonite (yielding 65% ee) exceeds even the corresponding phosphite and phosphoramidite. Keywords: phosphorus ligands; chirality; biaryls; asymmetric conjugate additions; phosphoramidites; phosphites; phosphonites; X-ray analyses