Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• reductive elimination. Starting from the ortho-N-(acyl)diaryl-λ3-iodanes 57, a combination of copper and palladium catalysis, in the presence of a phosphine ligand, induces the internal O-arylation of the proximal amide moiety, followed by a subsequent metal-catalyzed coupling-reaction with the resulting Ar

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• good to excellent yields (Scheme 11). These zwitterionic compounds can be further hydrolyzed to 1,3,5-trisubstituted pyrazoles, oxidized to 4-hydroxy-1,3,5-trisubstituted pyrazoles, transformed to 4-BPin derivative of 1,3,5-trisubstituted pyrazole or arylated under palladium catalysis to give 4-aryl

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• coupled with the alkyne under palladium catalysis. A broad range of TMS-substituted acetylenes 29 was converted efficiently under the optimized reaction conditions, forming the desired arylacetylenes 30 in good yields with high stereoselectivity. The applicable substrate scope is rather broad including

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• strategies to realise heterogeneous palladium catalysis [21]. Immobilisation of catalytic systems on solid supports can mitigate a lot of problems of homogeneous catalysts, for example, it allows a straightforward removal of the catalyst from the reaction system. However, most heterogeneous approaches

Palladium-catalyzed ortho-halogenations of acetanilides with N-halosuccinimides via direct sp² C–H bond activation in ball mills

• Zi Liu,
• Hui Xu and
• Guan-Wu Wang

Beilstein J. Org. Chem. 2018, 14, 430–435, doi:10.3762/bjoc.14.31

• corresponding N-halosuccinimides. Keywords: acetanilide; ball milling; C–H activation; halogenation; mechanochemistry; N-halosuccinimide; palladium catalysis; Introduction Aryl halides have been widely utilized in organic syntheses, which give access to a range of complex natural products [1][2]. However

Aminomethylation/hydrogenolysis as an alternative to direct methylation of metalated isoquinolines – a novel total synthesis of the alkaloid 7-hydroxy-6-methoxy-1-methylisoquinoline

• Benedikt C. Melzer,
• Jan G. Felber and
• Franz Bracher

Beilstein J. Org. Chem. 2018, 14, 130–134, doi:10.3762/bjoc.14.8

• material 3. Due to the very similar polarities of 3 and 4, chromatographic separation was very tedious, and only 34% of methyl compound 4 was isolated, accompanied by about 30% of starting material 3 and mixed fractions. Debenzylation of 4 by catalytic hydrogenation in methanol solution under palladium

• catalysis gave the alkaloid 1 in almost quantitative yield (Scheme 1). So this new metalation/methylation protocol offered a new approach to alkaloid 1 with an overall yield (22% from commercially available precursor 2) much higher than in the above mentioned previously published methods [11][12]. However

Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides

• Valentin A. Rassadin,
• Mirko Scholz,
• Anastasiia A. Klochkova,
• Armin de Meijere and
• Victor V. Sokolov

Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187

• Göttingen, Germany 10.3762/bjoc.13.187 Abstract A new and efficient approach to five- and six-membered benzannelated sultams by intramolecular C-arylation of tertiary 1-(methoxycarbonyl)methanesulfonamides under palladium catalysis is described. In case of the α-toluenesulfonamide derivative, an unexpected

• formation of a 2,3-diarylindole was observed under the same conditions. Keywords: arylation; fused-ring systems; indole formation; palladium catalysis; sultams; Introduction The sulfonamide functional group stands out as one of the most important pharmacophores. At the same time, cyclic sulfonamides

• compounds under palladium catalysis [28][29][30][31][32][33][34][35]. Disappointingly, an attempted cyclization of 3a employing one of the established precatalyst cocktails – Pd(OAc)2, Ph3P, NaH in dioxane – virtually failed. The target product 4 could be detected in the reaction mixture by 1H NMR

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• heterocyclic terpenes by subsequent (hetero)-Diels–Alder or [4 + 1]-cycloadditions with nitrenes is also depicted. Keywords: dimerization; heterocycles; isoprene; monoterpene; palladium catalysis; Introduction The dimerization of conjugated dienes represents a useful, highly atom economic and straightforward

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

• Alexei N. Kiselev,
• Olga K. Grigorova,
• Alexei D. Averin,
• Sergei A. Syrbu,
• Oskar I. Koifman and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

• our purpose, while the third system proved to be most versatile and afforded corresponding mono-, di-, tri- and even tetraarylated derivatives of porphyrins. Keywords: arylation; copper catalysis; heteroarenes; palladium catalysis; porphyrins; Introduction Porphyrins play an outstanding role in many

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• cyano group at the 5-position would lead to a push–pull system that could open new synthetic opportunities including the attack of nucleophiles at C-4. Metal cyanides such as KCN represent synthetically valuable C-1 building blocks that could efficiently be coupled by palladium catalysis to alkenyl

Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

• Chao Yang,
• Kai Lin,
• Lan Huang,
• Wei-dong Pan and
• Sheng Liu

Beilstein J. Org. Chem. 2016, 12, 2490–2494, doi:10.3762/bjoc.12.243

• : cyclization; indolo[3,2-a]carbazole; N-arylation; oxidative biaryl coupling; palladium catalysis; Introduction Many biologically active carbazole derivatives are of interest as drug-like templates. The indolo[3,2-a]carbazole skeleton, one of the isomeric indolocarbazoles, was firstly identified from nature

Et₃B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

• Ahlem Abidi,
• Yosra Oueslati and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2402–2409, doi:10.3762/bjoc.12.234

• chromatography over silica gel (gradient: petroleum ether/ether = 4:1) to give the pure allylated products 3–8 in moderate to good yields. Cyclic and acyclic MBH alcohols. X-ray crystal structure of tricyclic compound 6j. Proposed catalytic cycle involving palladium catalysis for Et3B-promoted allylation of

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

• Katrina Tait,
• Oday Alrifai,
• Rebecca Boutin,
• Jamie Haner and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

• oxabenzonorbornadiene; palladium catalysis; ring-opening reactions; Introduction Heterobicyclic alkenes undergo important chemical transformations to provide highly substituted cyclic and acyclic systems [1][2]. Oxabicyclic alkene 1 specifically can undergo a variety of chemical transformations to generate highly

• . Oxabenzonorbornadiene 1 and its derivatives are first cyclopropanated with diazomethane under palladium catalysis to afford 8 in good to excellent yields [29]. Cyclopropanated 8 has been predicted to undergo three distinct ring-opening mechanisms (Scheme 3). The first ring-opening type (type 1) involves the attack of

Rapid regio- and multi-coupling reactivity of 2,3-dibromobenzofurans with atom-economic triarylbismuths under palladium catalysis

• Maddali L. N. Rao,
• Jalindar B. Talode and
• Venneti N. Murty

Beilstein J. Org. Chem. 2016, 12, 2065–2076, doi:10.3762/bjoc.12.195

Synergistic chiral iminium and palladium catalysis: Highly regio- and enantioselective [3 + 2] annulation reaction of 2-vinylcyclopropanes with enals

• Haipan Zhu,
• Peile Du,
• Jianjun Li,
• Ziyang Liao,
• Guohua Liu,
• Hao Li and
• Wei Wang

Beilstein J. Org. Chem. 2016, 12, 1340–1347, doi:10.3762/bjoc.12.127

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

• Jakub Saadi,
• Christoph Bentz,
• Kai Redies,
• Dieter Lentz,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

• reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine. Keywords: 1,2-addition; aryl iodides; ketones; nucleophilic addition; palladium catalysis; Introduction For our systematic studies on samarium diiodide promoted cyclizations

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

• Michael Edmunds,
• Mohammed Abdul Raheem,
• Rebecca Boutin,
• Katrina Tait and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25

• ; oxabenzonorbornadiene; palladium catalysis; regioselectivity; ring-opening reactions; Introduction Palladium-catalyzed ring-opening reactions of 7-oxanorbornadiene with aryl iodides produce unsymmetrical, highly-substituted biphenyl derivatives making this reaction a very useful tool in organic synthesis [1][2][3][4

Recent developments in copper-catalyzed radical alkylations of electron-rich π-systems

• Kirk W. Shimkin and
• Donald A. Watson

Beilstein J. Org. Chem. 2015, 11, 2278–2288, doi:10.3762/bjoc.11.248

• nitroalkanes using palladium catalysis were known, prior to our work, no general catalytic methods for the alkylation of nitroalkanes existed. We envisioned that the catalytic generation of an alkyl radical under copper catalysis in the presence of a nitronate anion could lead to C-alkylated products. In

Efficient synthesis of π-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp²)–H bond arylations

• Fatiha Abdelmalek,
• Fazia Derridj,
• Safia Djebbar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2015, 11, 2012–2020, doi:10.3762/bjoc.11.218

(2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

• Armin de Meijere,
• Sergei I. Kozhushkov,
• Dmitrii S. Yufit,
• Christian Grosse,
• Marcel Kaiser and
• Vitaly A. Raev

Beilstein J. Org. Chem. 2014, 10, 2844–2857, doi:10.3762/bjoc.10.302

• to give the ester 45, which, after deallylation under palladium catalysis, was coupled with the tetrapeptides employing the HATU reagent in the presence of HOAt to give the corresponding hexadepsipeptides 51a–c. From the latter, the DCPM and Boc groups were cleaved off from both termini, leaving the

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

• Yiyang Liu,
• Marc Liniger,
• Ryan M. McFadden,
• Jenny L. Roizen,
• Jacquie Malette,
• Corey M. Reeves,
• Douglas C. Behenna,
• Masaki Seto,
• Jimin Kim,
• Justin T. Mohr,
• Scott C. Virgil and
• Brian M. Stoltz

Beilstein J. Org. Chem. 2014, 10, 2501–2512, doi:10.3762/bjoc.10.261

• the antipode of (+)-12 using the palladium-catalyzed enantioselective alkylation chemistry described above. We commenced a formal total synthesis of (−)-thujopsene (10) with the goal of improved efficiency compared to the Srikrishna/Anebouselvy route and to use enantioselective palladium catalysis to

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

• Christopher Albler,
• Ralph Hollaus,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2014, 10, 2230–2234, doi:10.3762/bjoc.10.231

• obtained allylic epoxides were regio- and stereoselectively opened with trimethylsilyl azide under palladium catalysis. Finally, a suitable deprotection protocol, starting with acidic acetate cleavage and ozonolysis was established. Peracetylation of the products simplifies purification and subsequent

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• palladium catalysis and subsequent decarboxylation yielded enone 118 as a single diastereomer. Addition of the Li anion of phosphonamide 24c to enone 118 afforded adduct 119 as a single isomer, with the attack occurring to the less hindered face of the enone. Further elaboration of the side chain was

• –Martin oxidation and deprotection of both allyl groups with formic acid under palladium catalysis finally provided berkelic acid (15). Thus, total synthesis of both epimers established the relative configuration of the side chain at C22 which was previously unknown, as well as helped to determine the

A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H)-furanones

• Jubi John,
• Eliza Târcoveanu,
• Peter G. Jones and
• Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 1462–1470, doi:10.3762/bjoc.10.150

• palladium catalysis afforded 4-substituted furanones in good to excellent yields. 4-Hydrazino-3(2H)-furanones could also be synthesized from diazo esters in excellent yields by utilising the developed strategy. We could also efficiently transform the substituted furanones to aza-prostaglandin analogues

• . Keywords: aza-prostaglandin analogue; 3(2H)-furanone; Mannich addition; palladium catalysis; tandem reaction; Introduction Organic chemists welcome the introduction of facile tandem protocols because of the advantages of multiple bond formation in one-pot processes, which in turn makes the process

• second one only in the presence of the Pd2dba3·CHCl3/dppe combination (Table 1, entry 13). Furanone 3 was obtained in 65% yield from the first reaction whereas the second reaction afforded only trace amounts of the desired product. Thus we can see that under palladium catalysis there is an increase in

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

• performed with a palladium catalyst in the presence of a weak base. Sometimes microwave irradiation was used to shorten the reaction time. Gilbertson et al. have converted a series of vinyl triflates 80b into the corresponding vinyl phosphine boranes 81b through palladium catalysis with HPPh2 (Table 9) [160