Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• copper(II) complexes is comparable with analogous complexes of bidentate ligands [5] (for TON and TOF parameters see Supporting Information File 1, part S5). The conversions were very high in almost all cases under set reaction conditions, except for pivalaldehyde. Here, the low conversions could be

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• using metal complexes as switching units (Figure 20). This concept named “weak link approach” (WLA) [78] uses square planar d8-transition metal complexes with two hemilabile bidentate ligands composed of a strong binding site (phosphorus) and a weaker one (generally sulfur, oxygen, selenium, or nitrogen

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• effective ligand in a variety of highly efficient aminocarbonylation reactions with Mo(CO)6 due to its strong basicity and accelerated release of CO from this reagent [21]. The reaction was then screened using two different bidentate ligands, XPhos and XantPhos, and using the previous reaction conditions

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• with >98% site-selectivity, in up to 98% yield and er = 96.5:3.5. Reactions involved a wide range of acyclic 1,1-disubstituted aryl olefins. Several C1-symmetric bidentate ligands derived from enantiomerically pure imidazolinium salts were examined for their efficiency. For example, a remarkable

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• )aminoalkanoic acids 86 (Scheme 15) [35][36]. This is a convenient way to synthesize γ-phosphonolactams 85. They further extended their method to synthesize cyclic O,O- and O,S-bidentate ligands with a P–N–P backbone. The substitution reaction of 3-bromopropylamine hydrogen bromide (87) and chloroethoxyphosphine

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• , C. tropicalis, and C. glabrata standard strains. A deep conformational survey was monitored using DFT calculations with the aim to explain the importance of the final conformation in the biological experimental results. Keywords: antituberculosis; bidentate ligands; DFT; nickel; palladium

Highly regio- and stereoselective phosphinylphosphination of terminal alkynes with tetraphenyldiphosphine monoxide under radical conditions

• Dat Phuc Tran,
• Yuki Sato,
• Yuki Yamamoto,
• Shin-ichi Kawaguchi,
• Shintaro Kodama,
• Akihiro Nomoto and
• Akiya Ogawa

Beilstein J. Org. Chem. 2021, 17, 866–872, doi:10.3762/bjoc.17.72

• as 1,2-bis(diphenylphosphino)ethane (Ph2PCH2CH2PPh2, dppe) are employed as bidentate ligands and are effective in controlling important catalytic reactions such as cross-coupling reactions [9][10][11][12][13][14][15][16][17][18]. 1,2-Bis(diphenylphosphino)ethylene (Ph2PCH=CHPPh2, dppen) is among

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• (Figure 2) [26][27]. In addition, 1-acyl-5-hydroxypyrazolines are bidentate ligands for zinc complexes and by virtue of being ring tautomers of β-enolhydrazones they can also act as tridentate ligands for nickel [28] and tin [29][30] complexes. In contrast, dimethylzinc forms dimeric complexes where the 1

Design of a double-decker coordination cage revisited to make new cages and exemplify ligand isomerism

• Sagarika Samantray,
• Sreenivasulu Bandi and
• Dillip K. Chand

Beilstein J. Org. Chem. 2019, 15, 1129–1140, doi:10.3762/bjoc.15.109

• ]. Complexation of cis-protected palladium(II), i.e., (PdL’) or bare palladium(II) with non-chelating bidentate ligands is known to afford a series of (PdL’)mLm or PdmL2m-type self-assembled coordination complexes [5]. Pd2L4-type cages are the simplest representatives among the PdmL2m-type complexes, yet most

Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands

• Tegene T. Tole,
• Johan H. L. Jordaan and
• Hermanus C. M. Vosloo

Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19

• bidentate ligands investigated by a number of research groups [5]. The pyridinyl alcohol found its way to the Grubbs-type complexes from research by Van Der Schaaf and co-workers on the Schrock-type analogues [6][7]. Grubbs 1-type complexes 3a–f (Figure 2) were used to catalyse the ring-closing metathesis

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• -phenanthroline) as the catalyst, 4a-Me was obtained in 86% yield after esterification. Other bidentate ligands such as bpy, phen, and dppe were not suitable for this reaction. Control experiments revealed that both the Co catalyst and the Mn reductant were indispensable to the reaction. The carboxylation of

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• doped films, OLED devices were fabricated showing remarkable efficiency attaining EQE of 21.5% at a luminance of 1029 cd m−2 with small roll-off [21]. These performances are the best reported so far for such a practical luminance. Systems based on bidentate ligands In the past, the most common synthetic

[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

• -phenylbut-1-yne [119] tridentate tris(benzimidazole) ligands completely failed and tris(triazole) ligands gave only poor to moderate yields (16–65%) even at 100 °C, whereas all the bidentate ligands (phenanthrolines L1, L2 and diimidazo[1,2-a:2',1'-c]quinoxalines L3–L6) were found to be more efficient both

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• catalysts. However, copper catalysts often have a low catalytic activity to activate the C–Hal bond. Fortunately, along with the development of various bidentate ligands, the copper-catalyzed C–O coupling reaction has been extensively applied in the synthesis of phenols from aryl halides. However, the

•  11). Aryl iodides and electron-deficient aryl bromides and chlorides were converted to the corresponding phenols. A broad range of functional groups are well tolerated under their optimum condition. Besides the opening work using TMHD by the Taillefer group, other O,O-bidentate ligands also played

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• anthraquinones. Further attempts to apply the Cu-based catalytic system in this reaction with L-proline and other commonly used N,N, N,O, and O,O bidentate ligands were fruitless. Previously, some of us successfully used the classic conditions of the Buchwald–Hartwig amination for the preparation of bis-amino

• with copper cation in comparison to bidentate ligands 5c and 5d. However, the cholane skeleton in 5c and 5d can be useful for integration of these ligands into lipophilic membranes. Conclusion Cu- and Pd-catalyzed cross-coupling reactions were applied for the preparation of arylamino derivatives of

From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer

• Ming Liu,
• Jan C. Namyslo,
• Martin Nieger,
• Mika Polamo and
• Andreas Schmidt

Beilstein J. Org. Chem. 2016, 12, 2673–2681, doi:10.3762/bjoc.12.264

• , MICs) and vice versa [34]. Herein, conjugated mesomeric betaine 2-(1-butyl-1H-imidazolium-3-yl)phenolate, its tautomeric NHC and its anionic NHC are shown to serve as monodentate and bidentate ligands, respectively. Results and Discussion Salt 5 is available via a three-step procedure [35

• ), 6.72 ppm, and 5.81 ppm, respectively. Single crystals of [Rh(7)3] (11) were obtained by slow evaporation of a concentrated solution of 11 in a mixture of EtOAc and MeOH. The single crystal X-ray analysis proved that three anionic N-heterocyclic carbenes 7 serve as bidentate ligands, respectively

• –Ccarbene bonds have lengths between 184.06(19) pm and 184.82(19) pm, respectively. These values correspond to literature-known bond lengths of cis arranged bidentate ligands around Ni [42][43][44], but, as expected, they differ from those of [(PEt3)(Ph)Ni(imidazo[1,5-a]quinolin-9-olate-1-ylidene)] [45] as

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• absorber; non-fullerene acceptor; zinc(II) complex; Introduction Azadipyrromethenes (ADPs) (Figure 1a) are a class of monoanionic bidentate ligands with strong absorption in the visible and near IR range. Their absorbance and emission properties can be readily tuned through structural modifications and

Olefin metathesis in air

• Lorenzo Piola,
• Fady Nahra and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

• quantitative yields in the RCM, CM and ene–yne reactions. Furthermore, complexes 33 and 85 were able to perform the RCM reactions under the same conditions, with yields ranging from moderate to excellent (Figure 15). Schiff bases Schiff bases in metathesis are usually O,N-bidentate ligands and represent an

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

• Iris Binyamin,
• Shoval Meidan-Shani and
• Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

• fact that the γ-hydroxypropyl substituent, which results directly from the ring opening of the phospholane, could provide a second ligation site upon complexation of the corresponding phosphines to a transition metal catalyst. These P,O bidentate ligands are quite useful in organometallic compounds

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

• –phosphido intermediate was beneficial for the alkylation. The scope of the reaction was investigated using diverse benzylic bromides 22b and secondary phosphines 36b. Bidentate ligands 40 and 41 were also synthesized [61][62]. This procedure was also restricted to benzylic halides. High enantiomeric

Garner’s aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

• Mikko Passiniemi and
• Ari M.P. Koskinen

Beilstein J. Org. Chem. 2013, 9, 2641–2659, doi:10.3762/bjoc.9.300

• metal-acetylide with terminal alkynes, such as 40. The phosphine ligand had to be monodentate; bidentate ligands gave a lot lower yields. Their catalyst system worked very efficiently with many carbonyl electrophiles, also with Garner’s aldehyde (R)-1. The reaction of 1 with 40 gave 41 with high

The first example of the Fischer–Hepp type rearrangement in pyrimidines

• Inga Cikotiene,
• Mantas Jonusis and
• Virginija Jakubkiene

Beilstein J. Org. Chem. 2013, 9, 1819–1825, doi:10.3762/bjoc.9.212

• preparation of condensed pyrimidine derivatives [27][28], have an interesting crystal structures [29][30][31], can be useful as bidentate ligands [32][33][34], and represent a class of biologically active compounds [35][36][37][38][39]. Results and Discussion The starting compounds 1 were prepared by the

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• ) and solvent (S17) forms [53]. Energetically accessible T-shaped species can also be intermediates in the site exchange of bidentate ligands of square-planar complexes. Fluxional motions of the 2,9-dimethyl-1,10-phenanthroline ligand (dmphen) have been observed in cationic complexes as [Pt(Me)(NN)(L

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

•  2) [29][30]. The reactions favor the formation of Z isomers, which results from photoinduced isomerization of initially formed E isomers. Ogawa’s diphosphination is thus potentially useful for the synthesis of (Z)-1,2-diphosphanyl-1-alkenes, which can serve as bidentate ligands. Morse developed

Palladium-catalyzed synthesis of N-arylated carbazoles using anilines and cyclic diaryliodonium salts

• Stefan Riedmüller and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2013, 9, 1202–1209, doi:10.3762/bjoc.9.136

• angle of the phosphines 99° and 93°, respectively) (Table 1, entry 5 and 7). When using bidentate ligands with bite angles higher than 100° (DPEphos 104°, Xantphos 108°) the reaction is more efficient and the yield increases significantly. Next, we asked ourselves, whether other palladium salts could be