Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• )PF6 (E1/2*III/II = +1.21 V, E1/2III/II = −1.37; E1/2IV/*III = −0.89, E1/2 IV/III = +1.69 V) [74] would permit efficient radical generation and C(sp3)–C(sp3) bond formation either by challenging selective radical–radical cross-coupling or by radical addition to a π-bond, enabling a rare example of

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• Xian-Lin Chen Hua-Li Qin School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, PR China 10.3762/bjoc.19.68 Abstract A SO2F2-mediated ring-opening cross-coupling of cyclobutanone oxime derivatives with alkenes was developed for

• the construction of a range of δ-olefin-containing aliphatic nitriles with (E)-configuration selectivity. This new method features wide substrate scope, mild conditions, and direct N–O activation. Keywords: direct N–O activation; E-selectivity; nitrile synthesis; ring-opening cross-coupling; sulfuryl

• of novel synthetic methods and strategies toward nitrile group construction continues to be a focus for synthetic chemists. The cross-coupling reactions of C–C bonds catalyzed by transition-metal complexes play a crucial role in modern organic synthesis, as they make it feasible to synthesize complex

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• on subsequent deprotonation gives the branched alkylated product 4. Whereas, in case of styrene 3 a 1,2-insertion takes place possibly due to the formation of the stable benzallylic species 8, which on deprotonation gives the linear alkylated product 5. The C–H activation/C–C cross-coupling reaction

• cross-coupling of pyridine N-oxides with nonactivated secondary (2°) alkyl bromides [51]. The cross-coupling is difficult to achieve as the Pd-catalyzed SN2 process is sensitive towards the steric bulk of the secondary or tertiary alkyl electrophiles. The optimized conditions for the ortho-alkylation of

• Heck cross-coupling [69][70]. However, researchers have developed various methods for the transition-metal-catalyzed C(sp2)–H olefination using various types of alkenes as coupling partners [71][72][73]. This part of the review covers reports for the alkenylation of pyridine with terminal alkynes

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• ]azepine and tetrabromothiophene-S,S-dioxide, followed by oxidative aromatization in the presence DDQ to afford compound 25 in an overall 75% yield. Suzuki−Miyaura cross-coupling reaction of compound 25 with (4-ethylphenyl)boronic acid in the presence of Pd(CH3CN)2Cl2, SPhos, and K3PO4 then furnished the

• Sonogashira cross-coupling reaction of phenylacetylene 50 and 1,4-dibromotetrafluorobenzene. The resulting bis[aryl(ethynyl)]tetrafluorobenzene 59 was able to undergo a 2-fold [4 + 2] cycloaddition reaction with cyclopentadienone 2, affording polyaromatic 60 in a 70% yield. The final step was the Scholl

• benzo[b]naphtho[2,3-f]oxepine 66 with tetrabromothiophene-S,S-dioxide in toluene followed by oxidative aromatization in the presence of DDQ afforded tetrabrominated aromatics 67 in an 81% yield. Subsequently, fourfold Suzuki–Miyaura cross-coupling of polybrominated compound 67 was performed, affording

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• ][17]. The Zn-catalyzed cross-coupling of dialkyl 2-bromo-1-methylethylphosphonates 68 and trimethylsilyl but-3-ynyl ether (69) generated dialkyl 5-hydroxy-1-methyl-3-methylenepentylphosphonates 70 in 66–73% yields under ultrasonic irradiation in THF at 45–50 °C for 45 min followed by treatment with

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• , transformation to potassium trifluoroborate salt, hydrolysis, C–C cross-coupling, base-mediated elimination, radical C–B cleavage) [72]. Therefore, enantioenriched boronates are commonly applied intermediates in organometallic, medicinal, and other fields of chemistry. At the same time, some organoboronic acid

• highly beneficial scaffold which was successfully involved in diastereoselective Ni/photoredox dual-catalyzed cross-coupling reactions. Furthermore, rather than the stereoselective protonation, they have also demonstrated the successful trapping of the Cu enolate with benzaldehyde (Scheme 45B). This

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• analogues, whereas the variation of the acyl chlorides did not affect the reaction significantly. The synthetic application is demonstrated by formation of non-natural and natural dienone-containing terpenes such as β-ionone which was available in 4 steps and 6% overall yield. Keywords: cross coupling

• ethers 12 [19] and metal-catalyzed cross coupling of alkenes 13 and enones 14 [20][21] have been reported. However, these reactions face multiple disadvantages such as limited substrate scope, use of hazardous solvents and harsh reaction conditions such as high temperatures or acidic/basic conditions

• ][33][34][35][36][37][38][39][40] as well as in several total syntheses of natural products [41][42][43][44][45][46]. Especially the combination of hydrozirconation and Pd or Ni-catalyzed cross coupling was elaborated by several groups (Scheme 3) [47][48][49][50][51][52][53][54]. Negishi extended

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• sustainable synthetic procedures involving cheap, non-toxic and efficient additives is also discussed, as well as the mechanistic features guiding the reactivity of such catalytic systems. Keywords: catalysis; cross-coupling; insect pheromones; iron; Introduction Public health issues related to

• ]) are linear syntheses involving a great number of steps and purifications as well as cryogenic temperatures. Moreover, the introduction of the C=C unsaturation is achieved via a Wittig reaction or a Pd-catalyzed Sonogashira cross-coupling followed by a reduction by a borane reagent, methods which lead

• to overall processes with a low atom economy, generating a significant amount of chemical waste, and which can be expensive when noble metals such as palladium salts are required (Scheme 1). The high efficiency of transition-metal-catalyzed cross-coupling methods in C–C bond formation processes

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• °C and 0 °C, temperatures at which these organometallic reagents are also reported to be quite stable. The zincated dithiins can also be prepared by transmetalation of the magnesiated dithiins at −30 °C, and these organozinc reagents can then be used in room temperature Pd-catalyzed cross-coupling

• , including cross-coupling-type chemistries on a conformationally stable cis-vinyl zinc building block. 3 Diels–Alder reactivity of 1,4-dithiin-based dienophiles and dienes Vinyl sulfones and vinyl sulfoxides are classical synthetic equivalents of ethylene in Diels–Alder reactions, and have been widely used

Practical synthesis of isocoumarins via Rh(III)-catalyzed C–H activation/annulation cascade

• Qian-Ci Gao,
• Yi-Fei Li,
• Jun Xuan and
• Xiao-Qiang Hu

Beilstein J. Org. Chem. 2023, 19, 100–106, doi:10.3762/bjoc.19.10

• for the synthesis of isocoumarin scaffolds. Traditional synthetic strategies including 1) intramolecular cyclization of 2-alkenyl benzoic acids or o‑alkynylbenzoates (Scheme 1b, I) [6][7][8][9][10], 2) oxidation of isochromans (Scheme 1b, II) [11][12], or 3) metal-catalyzed cross-coupling/cyclization

• approach towards isocoumarins [17][18]. Pioneering examples relying on the Pd, Ru, and Ir-catalyzed C–H cross coupling of benzoic acids with alkenes and alkynes were realized by the groups of Miura [19], Lee [20], Ackermann [21], Zhang [22], Jiang [23], and Jeganmohan [24] et al. Despite these impressive

• recently, the same group developed an efficient Rh(III)-catalyzed C–H cross-coupling of enaminones with diazodicarbonyls for the divergent construction of isocoumarins and naphthalenes [27]. Moreover, Loh et al. disclosed a Rh-catalyzed formal [4 + 2] cycloaddition of enaminones with diazocarbonyls [28

Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• ” topics of the discipline under discussion. Cross-coupling reactions are also of importance in organophosphorus chemistry. Taddei and co-workers applied an alternative method to the classical Hirao reaction [1]. They utilized the Ni-catalyzed double Michaelis–Arbuzov reaction of bis(bromoaryl) species and

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• chemoselective manner [3]. The development of persistent radicals [4] as synthons in chemical synthesis, coupled with the advancements in generating and manipulating transient radicals [5] as cross-coupling partners in an array of chemical reactions, gives access to a wide variety of “new” retrosynthetic

• reactions of transition metal hydrides (Fe, Co, Mn, etc) with alkenes (e.g., Mukaiyama hydration) [20]. The last decade saw the development of milder methods for generating carbon-centered radicals as the advancement of their reactivity in cross-coupling reactions, the concept of photoredox catalysis [21

• nickel-mediated decarboxylative Giese reactions and decarboxylative radical zinc-mediated cross-coupling reactions of redox-active esters, established from previous works of the group [27][28], for the key C–C bonds of the diverse congeners. To this end, a hypothetical intermediate 3 was envisioned for

Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• -membered triflate 71 was synthesized from diketone 26 in 5 steps and 37% overall yield. Both fragments were assembled by a Sonogashira cross-coupling, affording 72 in 72% yield. In a first attempt, TBS protection was considered on the bicylo[3.2.1]octane. However, later in the strategy, the deprotection

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• introduction of an electron-withdrawing acetoxy group. The DABCO cation radical is less reactive compared to quinuclidine-derived cation radicals. It was involved in the Ni-catalyzed oxidative C–C cross-coupling involving aldehyde C–H bond cleavage with the formation of acyl radicals according to the proposed

• catalyzed by ABNO-type amine-N-oxyl radicals. Hydrogen atom transfer (HAT) and single-electron transfer (SET) as basic principles of amine cation radical oxidative organocatalysis. Electrochemical quinuclidine-catalyzed oxidation involving unactivated C–H bonds. DABCO-mediated photocatalytic C–C cross

• -coupling involving aldehyde C–H bond cleavage. DABCO-derived cationic catalysts in inactivated C–H bond cleavage for alkyl radical addition to electron-deficient alkenes under photoredox catalysis conditions. Electrochemical diamination and dioxygenation of vinylarenes catalyzed by triarylamines

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• was further confirmed through X-ray crystallographic analysis. With the key intermediate 10 in hand, we were in a position to test the planned two-step transformation including the palladium-catalyzed reductive cross coupling with HCO2H followed by Pd/C-catalyzed hydrogenation. To our surprise, the

• –Martin oxidation. At this stage, the pivotal C–H insertion step was tried under the reported conditions [34], and cyclopentenone 8 was successfully obtained. Further study with cross coupling or halogen–magnesium exchange shows this moiety is inert for functional group transformation. The attempt for

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• the cross coupling reaction. We also mention that we did not decide for a direct transformation [27][28] of 6-iodo-1-deazapurine into 6-hydroxy-1-deazapurine for reasons of solubility and desired regioselectivity of the subsequent nitration reaction. 1-Deazahypoxanthine Synthesis of 1

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• difluoroalkyl ethers (1), along with small amounts of fluoroalkenyl ethers (2), which were obtained from 1 via an E2-elimination mechanism (Scheme 1B) [14][15]. The fluoroalkenyl group in 2 is a potentially useful moiety that could participate in cross-coupling reactions for replacement of the bromine atom with

• HF from 1 provides 2 as an E/Z mixuture (E/Z = 1:1). We speculated that the stability of the E isomer was equal to that of the Z isomer under these conditions. To expand the scope of this reaction, we subjected product 2 to a Sonogashira cross-coupling reaction (Scheme 3). This gave a highly

• functionalized enyne structure that will be useful in various molecular transformations [27][28][29]. On the basis of a previous report, Sonogashira cross-coupling of 2 with trimethylsilylacetylene was performed with a bis(triphenylphosphine)palladium(II) dichloride. The reaction proceeded smoothly to give

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• order of addition of reactants to perform the transition-metal-catalyzed C–P cross-coupling reaction, often referred to as the Tavs reaction, employing NiCl2 as a pre-catalyst in the phosphonylation of aryl bromide substrates using triisopropyl phosphite. This new method was employed in the synthesis of

• three novel aryl diphosphonate esters which were subsequently transformed to phosphonic acids through silylation and hydrolysis. Keywords: arylphosphonic acids; cross-coupling reaction; phosphonate esters; transition-metal catalysis; Introduction Phosphonates and phosphonic acids are a very

• ][25][26]. These catalytic cross-coupling reactions tend to follow similar pathways to the Michaelis–Arbuzov reaction, with the inclusion of a catalytic intermediate step. A number of suitable catalysts have been identified, ranging from nickel(II) bromide and nickel(II) chloride, to palladium(II

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• peptide so that the thiol group in the sidechain could be used to place the molecule the array with the use of an electrochemically initiated Cu(I)-catalyzed cross-coupling reaction (Scheme 1) [9]. To this end, the Cu(I) catalyst needed for the reaction was generated at the electrodes by the reduction of

• for the confinement strategy to keep up. The result is a loss in confinement. It is important to point out that the reaction shown in Scheme 1 is not a typical electrosynthetic reaction. The cross-coupling reaction shown is a Cu(I)-catalyzed transformation that requires no recycling of a reagent

• 12 electrodes each functionalized with pyrene-butanol at various places on the array. For the placement reaction, the Cu(I)-catalyzed cross-coupling reaction used above (Scheme 1) was employed for 4 cycles (90 s on and 180 s off). The chemistry placed enough of the alcohol by the electrodes for the

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• cyclopropanes with arenes [29]. They have also been used in Pd-catalyzed cross-coupling reactions to react with hypervalent iodonium salts, organostananes, and vinyl epoxides [30][31][32]. Moreover, there are reports of them serving as oxidizing agents for alcohols [33]. Two papers have recently reported

Design, synthesis, and evaluation of chiral thiophosphorus acids as organocatalysts

• Karen R. Winters and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2022, 18, 1471–1478, doi:10.3762/bjoc.18.154

• cross-coupling [34] in excellent yield. Esterification of 6 with monomethyl H-phosphonate tert-butylamine salt [35] resulted in the mixed H-phosphonate ester 7 in excellent yield. Cyclization using our homolytic aromatic substitution methodology [36] gave P-heterocycle 8 in modest yield. Other methods

• cross-coupling, and 2) immobilization on a solid support via reduction and reaction of the aniline with an electrophile such as polystyrene isocyanate. DOPO scaffold We previously reported the syntheses of both enantiomers of 8-phenyl DOPO 3 [38]. The syntheses proceed in only three steps (including the

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• transition metal-catalyzed cross-coupling reactions broadly used for the preparation of different diarylacetylenes and, rarely, bis(chlorophenyl)acetylenes. Next, starting substituted benzaldehydes were treated with an excess of SOCl2 for 24 h at 25 °C. Corresponding substituted benzal chlorides 4 were

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

• Sebastien Curpanen,
• Per Reichert,
• Gabriele Lupidi,
• Giovanni Poli,
• Julie Oble and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

• -catalyzed cross-coupling reactions, such as arylation reactions catalyzed by Pd2(dba)3/CuI, as well as allylation and methylation reactions catalyzed by CuI⋅PPh3. C3-Benzyldimethylsilyl-appended furfurals are thus introduced as versatile platforms, providing a modular access to 3-substituted 2-furyl

• on the SiMe(OSiMe3)2 unit, which were readily converted through Pd- or Cu-catalyzed electrophilic substitution reactions into an array of furfurals decorated at C3 with carbon- or heteroatom-containing substituents (Scheme 1). Conversely, all of our subsequent efforts to achieve cross-coupling

• cross-coupling chemistry [30][31], could be accessed from 2-[(3-benzyldimethylsilyl)furyl] carbinols. C3–Si bond functionalization through siloxane formation In an attempt to isolate cyclic siloxane 16, we then considered a protocol reported by Anderson and co-workers to prepare cyclic siloxanes by