A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• performance to Cs2CO3 including the lack of methyl ester hydrolysis, but a lower price. The catalyst's performance had a more significant influence on the reaction results than the base. Both phosphine catalysts as well as the second generation of the Buchwald–Hartwig catalyst [47][48] gave similar results

• , the best results were achieved with Pd(dppf)Cl2. The conversion was among the highest overall regardless of base and the removal of the catalyst afterwards was most straightforward. While the phosphine-based catalysts tend to be oxidised during the workup, resulting in the contamination of the

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• using tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) to obtain methyl cinnamate (44) in good yield (Scheme 18) [50]. Herein, the phosphine group attacks the acid fluoride to give intermediate 55, fluoride attack then triggers methoxy group release. Toste and co-workers (2021) synthesized N-trifluoromethyl

• using this method. Furthermore, Dai and co-workers (2020) employed alkenylboronic acid 209 and O-methyl S-p-tolyl thiocarbonate to prepare methyl cinnamate (44) catalyzed by Pd2dba3 in the presence of Cu(I) thiophene-2-carboxylate (CuTC) and the ligand tri(2-furyl)phosphine (TFP). The reaction proceeds

• –380 via an α-borylation–protodeborylaton mechanism involving intermediates 381 and 382 (Scheme 83A) [141]. On the one hand, Vilotijevic and co-workers (2021) reported a phosphine-mediated partial hydrogenation of conjugated alkynes using water as the hydrogen source to obtain the corresponding cis

Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality

• Natsume Akimoto,
• Kaho Takaya,
• Yoshio Kasashima,
• Kohei Watanabe,
• Yasushi Yoshida and
• Takashi Mino

Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83

• , compound 7 has a primary alkyl group (n-propyl). This difference reduces steric hindrance and lowers the rotational barrier around the carbon–nitrogen bond, increasing the likelihood of racemization. Results and Discussion N-Propyl-N-cinnamoylamide 7 was prepared from phosphine oxide 8 [32] via an SNAr

• reaction with nucleophilic lithium amide from n-propylamine, the reduction of phosphine oxide 9 by trichlorosilane/triethylamine, and the N-acylation of 10 with cinnamoyl chloride in three steps (Scheme 1). We also analyzed amide compound 7 by HPLC analysis using a chiral stationary phase column with a CD

• steps from phosphine oxide 8. Chiral HPLC analysis confirmed its axial chirality at the C(aryl)–N(amide) bond. The optical resolution of (±)-7 yielded (+)-7 and (−)-7. The racemization barrier of (−)-7 in n-dodecane was determined to be 25.0 kcal/mol at 25 °C, with a half-life of approximately 1.3 days

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• of a wide range of these compounds (25 compounds of phosphonylated 3,3-spiroindolines) in a convenient process. The C–P bond formation reaction of phosphine oxides with N-Boc-indolines was carried out in the presence of Cp2Fe, but the reaction did not occur in its absence. When the reaction was

• phosphonates and phosphine oxides using a nickel catalyst. The use of nickel complex is an important and primary factor in the C–P coupling process. Notably, the inexpensive and environmentally readily available nickel catalysis was more effective for phosphorylation than other 3D metals. Moreover, it

• electrochemical method. They have synthesized 30 different thiazole phosphine oxides with up to 91% yield at room temperature without using an external metal or oxidant. The reaction was carried out in an undivided cell using glassy carbon as the anode and foamed copper as the cathode electrodes at a constant

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• compounds using dihalomethanes (Scheme 27) [79]. They developed a three-component reaction between amines (mainly tertiary amines), a dihalomethane, and a P(OH) species (like phosphonate, phosphinate, or secondary phosphine oxide) under catalyst-free conditions to afford α-amino phosphorus compounds 35. The

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• their stereodirecting effect, Boltje et al. demonstrated a series of six ether, tertiary amide, and phosphine oxide-based auxiliary O-2 protecting groups [151]. The results indicated increased 1,2-cis selectivity with tertiary amide and phosphine-based protecting groups in comparison to an ether-based

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• yields. The single crystal structure of the compound 6e was determined by X-ray diffraction (Figure 3). The similar reaction of more nucleophilic tri(tert-butyl)phosphine and MBH carbonate of isatin resulted in a mixture of products. After carefully screening the reaction conditions, we found that DABCO

• successfully promoted reaction of tri(tert-butyl)phosphine and MBH carbonates of isatins in toluene at 80 °C for three hours. These conditions resulted in mixtures of conjugated triene cis/trans-isomers 7a–d and 8a–d with nearly 4:1 ratios (Table 2). It should be pointed out that similar conjugated trienes

• addition of Lewis base is needed. When triphenylphosphine or tri(n-butyl)phosphine were involved in the reaction, the similar SN2’ substitution of tri(n-butyl)phosphine with the elimination of carbon dioxide and tert-butoxide anion gives the phosphonium salt C. Then, the deprotonation of phosphonium salt C

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• dioxazolone bearing a phenyl group showed no reactivity toward benzoyl amidine under the optimized reaction conditions. Instead, the authors employed a less bulky copper iodide catalyst in the absence of phosphine, successfully affording aryloyl amidine 10f. Furthermore, the electron-rich ethynylanisole

• to yield the stable intermediate INT-21. This intermediate releases the N-acyl iminophosphorane 16 through the incorporation of another organic phosphine, thereby regenerating the active copper species 17. 1.6 Synthesis of N-sulfenamides In 2022, the research groups of Wang and Chen introduced a

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• assigning specific contributions of each to the observed binding affinities. Even so, 1H NMR titration experiments with phosphine oxides still allow us to partially resolve these two forces by monitoring the proton of the CF2H group. Such issues are particularly salient when quantification methods that rely

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

• Takeshi Fujita,
• Haruna Yabuki,
• Ryutaro Morioka,
• Kohei Fuchibe and
• Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

• , entry 3). Reducing the catalyst loading to 5 mol % slightly affected the yield of 3bb, which was 90% (Table 1, entry 4). Next, we evaluated various additives with 5 mol % of Ni(cod)2 to stabilize regenerated zero-valent nickel species (Table 1, entries 5–8). While phosphine ligands such as triphenyl

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• phosphine oxide (PO) groups have recently received considerable attention for their high thermal stability and unique optoelectronic features, and thus being widely applied in organic light-emitting diodes (OLEDs) [1][2]. To date, tremendous efforts have been devoted to the development of a variety of high

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• ; phosphine ligand; pyridine amides; Introduction Transition-metal-catalyzed synthetic reactions have recently attracted much attention in synthetic organic chemistry [1][2]. C–H Arylation reactions catalyzed by a transition metal are of particular interest because these reactions involve rather superior

• effective to afford 2a in 94% yield. The reaction was then carried out with several pyridine derivatives including amide derivatives composed of 6-methylpicoline (1b) and unsubstituted picoline (1c) as summarized in Table 2. When the reaction was examined in the absence of a phosphine ligand, the yields of

• palladium catalyzed C–H arylation to pyridine derivatives. The cyclization reaction proceeded in a moderate to excellent yield when an appropriate phosphine ligand was employed. The reaction is expected to be useful for the synthesis of functional materials, and bioactive molecules in a facile manner

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• -rhamnosides β-16g–j were prepared from the corresponding anilines as exemplified above for the synthesis of β-16a. Treatment of β-16a,g–j with tris(diethylamino)phosphine resulted in formation of dimers β-59a–e in good yields (Scheme 36) [58]. Deprotection afforded the desired isoindigo-N,N‘-dirhamnosides β

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

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

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• previous study by Thorand [44], we performed the reaction between fluorine-containing vinyl ether 1a and 1.05 equiv of trimethylsilylacetylene (5a) to afford the corresponding enyne 3a in 55% yield (Table 2, entry 1). Cross-coupling utilizing a palladium(II) catalysts containing phosphine ligands produced

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• alkyne probe from the CuAAC reaction mixture or by increasing the concentration of the reducing agent such as tris(2-carboxyethyl)phosphine (TCEP). The reversed chemical proteomics approach in which the azide probe and alkyne tag are used suffers from similar unspecific reactivity of the terminal alkyne

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• interelement compounds such as Ph2P–PPh2 and Ph2P(S) –PPh2 to phenyl isocyanide, but the addition did not proceed at all. This is most likely due to the bulkiness of the Ph2P and Ph2P(S) groups (Scheme 8) [39]. In sharp contrast, the addition of a germyl phosphine (Et2P–GeEt3) to phenyl isocyanide was reported

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• moderate yield (entry 1: 42%, cf. batch reaction: 76%). Lowering the reaction temperature to 25 °C reduced the yield (Table 1, entry 2: 35%), but decreasing the amount of the phosphine ligand from 20 mol % to 5 mol % markedly improved the yield (Table 1, entry 3: 53%). Even when the flow rate was increased

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• the presence of Cs2CO3. To explore the possibility of N2-selectivity, we hypothesized that the phosphine intermediate of a Mitsunobu reaction could provide chelation control, directing alkylation to the indazole N2-atom while using identical alcohols as described above. Thus, we subjected 6 to simple

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• preparing spiro α-methylene-β-lactones from different steroidal propargylic alcohols [13]. The procedure involves a one-pot Pd-catalyzed cyclocarbonylation of alkynols using 5 mol % of Pd(CH3CN)2Cl2 as a catalyst precursor and 30 mol % of 2-(dibutyl)phosphine-1-(2,6-diisopropylphenyl)-1H-imidazole as

• phosphine-based ligand (L). This methodology was applied to the alkynol moiety of ethinylestradiol (8) (86% yield), and alkynols derived from ethisterone, levonorgestrel, lynestrenol, and epiandrosterone (epi-ADT), obtaining excellent yields (85–93%) and high diastereoselectivity (dr > 20:1) in all cases. α

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• thus wondering if we could extend this ammonium salt-catalyzed β-selective allenoate functionalization strategy to other amino acid classes. Azlactones 1 have previously been used for γ-selective additions to allenoates under chiral phosphine catalysis [28]. In addition, glycine Schiff base derivatives

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• [28] introduced the photoredox-catalyzed hydroacylation of styrene derivatives via deoxygenation of challenging aliphatic carboxylic acids (Scheme 1). The deoxygenation was promoted by phosphine reagents to form acyl radicals. The acyl radicals reacted with the C=C bond and formed the expected product

• . Appropriate selection of the phosphine reagent was the key to success in the process. Due to the lower oxidation potential, electron-rich PMe2Ph preferentially transferred a single electron to the excited state of the photocatalyst rather than the alkene, which was essential for obtaining the desired product

• to a phosphine radical cation. The proposed mechanism involves the formation of a phosphine radical cation via SET from photoexcited [Ir(III)] complex. Subsequently, the benzylic alcohol initiates a polar nucleophilic attack on the phosphine radical cation, forming a phosphoranyl radical. This

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• )phosphine ligand (PN3P) (Mn3) and studied N-methylation reactions in the presence of t-BuOK (20 mol %) at 120 °C for 24 h in toluene [36]. This catalytic system tolerated various functional groups, including nitro, ester, amide, and ketones and gave moderate to good yields (42–98%) of the mono-N-methylated

• condenses with hydrazine followed by reduction and condensation with another aldehyde to afford the N-substituted hydrazones (Scheme 8). Balaraman and co-workers established a phosphine-free manganese catalyst generated in situ from a manganese precursor and a ligand for the N-alkylation of anilines with

•  10). However, sulfonamides with electron-withdrawing groups attached to the aromatic ring (e.g., 4-NO2, 4-CN) were found incompatible with the conditions. Ke and co-workers described an exciting example of a phosphine-free Mn(I)-NHC catalyst for the N-alkylation of amines with alcohols at room