The cores of many types polymers, ligands, natural products, and pharmaceuticals contain biaryl or substituted aromatic structures, efficient methods synthesizing these structures are crucial to the work a broad spectrum organic chemists. Recently, Pd-catalyzed carbon−carbon bond-forming processes, particularly Suzuki−Miyaura cross-coupling reaction (SMC), have risen in popularity for this purpose. SMC has advantages over other constructing moieties, including mild conditions, high tolerance...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRational Development of Practical Catalysts for Aromatic Carbon−Nitrogen Bond FormationJohn P. Wolfe, Seble Wagaw, Jean-François Marcoux, and Stephen L. BuchwaldView Author Information Department Chemistry, Massachusetts Institute Technology, Cambridge, 02139 Cite this: Acc. Chem. Res. 1998, 31, 12, 805–818Publication Date (Web):October 21, 1998Publication History Received26 March 1998Published online21 October inissue 1 December...

Suzuki−Miyaura coupling reactions of aryl and heteroaryl halides with aryl-, heteroaryl- vinylboronic acids proceed in very good to excellent yield the use 2-(2',6'-dimethoxybiphenyl)dicyclohexylphosphine, SPhos (1). This ligand confers unprecedented activity for these processes, allowing be performed at low catalyst levels, prepare extremely hindered biaryls carried out, general, chlorides room temperature. Additionally, structural studies various 1·Pd complexes are presented along...

Dialkylbiaryl phosphines are a valuable class of ligand for Pd-catalyzed amination reactions and have been applied in range contexts. This perspective attempts to aid the reader selection best choice reaction conditions this most commonly encountered practically important substrate combinations.

Mixtures of palladium acetate and o-(di-tert-butylphosphino)biphenyl (4) catalyze the room-temperature Suzuki coupling aryl bromides chlorides with 0.5−1.0 mol % Pd. Use o-(dicyclohexylphosphino)biphenyl (2) allows couplings to be carried out at low catalyst loadings (0.000001−0.02 Pd). The process tolerates a broad range functional groups substrate combinations including use sterically hindered substrates. This is most active system in terms reaction temperature, turnover number, steric...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA General and Efficient Copper Catalyst for the Amidation of Aryl Halides N-Arylation Nitrogen HeterocyclesArtis Klapars, Jon C. Antilla, Xiaohua Huang, Stephen L. BuchwaldView Author Information Department Chemistry Massachusetts Institute Technology Cambridge, 02139 Cite this: J. Am. Chem. Soc. 2001, 123, 31, 7727–7729Publication Date (Web):July 12, 2001Publication History Received18 May 2001Revised22 June 2001Published online12 July...

A facile Pd-catalyzed method for the preparation of a wide variety aryl amines from bromides and has been developed [Eq. (a)]. Noteworthy features this include experimental simplicity, tin/boron-free conditions, broad spectrum potential substrates.

Unprecedented scope, reactivity, and stability are displayed by a new catalyst system. This was demonstrated with general efficient syntheses of sterically hindered (hetero)biaryls (see examples shown), mild coupling reactions alkyl boron derivatives, rapid aryl chlorides at room temperature. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z53615_s.pdf or from author. Please note: The publisher not responsible content...

An experimentally simple and inexpensive catalyst system was developed for the amidation of aryl halides by using 0.2−10 mol % CuI, 5−20 a 1,2-diamine ligand, K3PO4, K2CO3, or Cs2CO3 as base. Catalyst systems based on N,N'-dimethylethylenediamine trans-N,N'-dimethyl-1,2-cyclohexanediamine were found to be most active even though several other ligands could used in easiest cases. Aryl iodides, bromides, some cases chlorides can efficiently amidated. A variety functional groups are tolerated...

Three Fluorines at Once The trifluoromethyl (CF 3 ) group is playing an increasingly important role in the design of pharmaceutical and agrochemical compounds. CF a powerful attractor electron density within given molecular framework, recently fluorine-hydrocarbon interactions have emerged as distinct complement to more traditional hydrophilic/hydrophobic interplay that governs docking between small molecules proteins. Cho et al. (p. 1679 now present efficient method for appending groups...

The first general method for the Pd-catalyzed amination of aryl tosylates and benzenesulfonates was developed utilizing ligand 1, which belongs to a new generation biaryl monophosphine ligands. In addition, catalyst system time enables amidation arenesulfonates aqueous protocols that do not necessitate use cosolvents. substrate scope has been significantly expanded include halides containing primary amides free carboxylic acid groups. case multifunctional substrates, can provide selectivity...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPalladium-Catalyzed Aromatic Aminations with in situ Generated AminostannanesAnil S. Guram and Stephen L. BuchwaldCite this: J. Am. Chem. Soc. 1994, 116, 17, 7901–7902Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://pubs.acs.org/doi/10.1021/ja00096a059https://doi.org/10.1021/ja00096a059research-articleACS PublicationsRequest reuse permissionsArticle...

A unique combination of steric and electronic properties appears to determine the effectiveness phosphanyl-substituted biphenyls as ligands in palladium-catalyzed aminations Suzuki coupling aryl chlorides at room temperature [Eq. (1)]. The oxidative addition step is greatly accelerated, transmetalation (or Pd-N bond formation) reductive elimination processes are facilitated. Use these allows for very low catalyst loadings (as little 10(-6) mol % Pd). R"=cyclohexyl, tert-butyl.

A new method in which a series of substituted carbazoles is efficiently produced by the combination an amide and arene described. The key feature this palladium-catalyzed tandem directed C−H functionalization arylation. tolerates substitution on either ring biaryl substrates, products can be assembled simple two-step protocol from readily available reagents. Pd(0) species generated are reoxidized to Pd(II) presence Cu(OAc)2 atmosphere oxygen.

Palladium complexes supported by (o-biphenyl)P(t-Bu)2 (3) or (o-biphenyl)PCy2 (4) are efficient catalysts for the catalytic amination of a wide variety aryl halides and triflates. Use ligand 3 allows room-temperature many chloride, bromide, triflate substrates, while 4 is effective functionalized substrates reactions acyclic secondary amines. The perform well large number different substrate combinations at 80−110 °C, including chloropyridines triflates using 0.5−1.0 mol % Pd; some proceed...

A series of easily prepared, phosphine-ligated palladium precatalysts based on the 2-aminobiphenyl scaffold have been prepared. The role precatalyst-associated labile halide (or pseudohalide) in formation and stability palladacycle has examined. It was found that replacing chloride previous version precatalyst with a mesylate leads to new class improved solution are readily prepared from wider range phosphine ligands. differences between reported here explored. In addition, reactivity latter...

Facile Fluorination Fluorine atoms have become a useful substituent in pharmaceuticals. However, they remain challenging to introduce synthetically because present methods for carbon-fluorine bond formation require either corrosive conditions or somewhat exotic, and thus expensive, reagents. A sticking point has been the failure of traditional palladium catalysts couple aryl groups with coordinated fluoride. Watson et al. (p. 1661 , published online 13 August; see Perspective by Gouverneur )...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAn Improved Catalyst System for Aromatic Carbon−Nitrogen Bond Formation: The Possible Involvement of Bis(Phosphine) Palladium Complexes as Key IntermediatesJohn P. Wolfe, Seble Wagaw, and Stephen L. BuchwaldView Author Information Department Chemistry Massachusetts Institute Technology Cambridge, 02139Cite this: J. Am. Chem. Soc. 1996, 118, 30, 7215–7216Publication Date (Web):July 31, 1996Publication History Received13 March 1996Published...

The utility of copper-mediated cross-coupling reactions has been significantly increased by the development mild reaction conditions and ability to employ catalytic amounts copper. use diamine-based ligands important in these advances this perspective we discuss systems, including choice applications synthesis pharmaceuticals, natural products designed materials.

Copper closes the ring: Benzimidazoles are synthesized from amidines through a copper-catalyzed CH functionalization/CN bond-forming process. The method tolerates broad range of functional groups and provides benzimidazoles in up to 89 % yield. Best results obtained by using 15 mol Cu(OAc)2, 2–5 equivalents HOAc as additive, oxygen stoichiometric reoxidant (see scheme). Supporting information for this article is available on WWW under...