A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• )L1 is given for comparison. Selected examples of the chiral ligands used for synthesis of the Ni(II)–Schiff base complexes. Synthesis of the chiral ligand L7 and its Ni(II) complexes with glycine, serine, dehydroalanine, and cysteine derivatives. The yields and the thermodynamically controlled

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

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• prepared based on the reaction of Zn(II) or Ni(II) complexes of 5,10,15,20-tetrakis(4-amino-2,3,5,6-tetrafluorophenyl)porphyrin and chlorin with maleic anhydride. Porphyrin maleimide derivatives were also prepared by the reaction of 5,10,15,20-tetrakis(4-azido-2,3,5,6-tetrafluorophenyl)porphyrinato Zn(II

• 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (1) [35] was used as starting compound. The synthesis includes the metallation of the free base porphyrin 1 with an excess of zinc acetate or nickel acetate resulting in the corresponding porphyrin Zn(II) and Ni(II) complexes 2a [36] and 2b [37], respectively

Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones

• Alexander N. Reznikov,
• Anastasiya E. Sibiryakova,
• Marat R. Baimuratov,
• Eugene V. Golovin,
• Victor B. Rybakov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2019, 15, 1289–1297, doi:10.3762/bjoc.15.127

• nitroalkenes in the presence of Ni(II) complexes with various chiral vicinal diamines was studied. This reaction provides convenient access to non-racemic 4-nitro-2-sulfonylbutan-1-ones with two stereocenters with high yield and excellent enantioselectivity (up to 99%). It has been established that the

• that the reaction of β-keto phosphonates with nitroalkenes in the presence of Ni(II) complexes with chiral vicinal diamines was carried out not only with excellent enantioselectivity, but also diastereoselectivity [55]. Moreover, β-keto sulfoxides react with nitroalkenes under catalysis by Ni(II

• Initially we carried out a screening of catalysts using the Ni(II) complexes 7a–h with chiral vicinal diamines L1–L8 (Figure 2) in a model reaction of 1-phenyl-2-(phenylsulfonyl)ethan-1-one (5a) with ω-nitrostyrene (6a). The results of the study are shown in Table 1. The Michael addition of the β

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• azobenzene-carboxylates has been synthesized and characterized in solution and solid state. The diamagnetic Cd(II) and Zn(II) and the paramagnetic Ni(II) complexes were found to be isostructural, with the co-ligands bound via bridging carboxylate functions, a bowl-shaped structure of the supporting [M2L]2

Rhodium, iridium and nickel complexes with a 1,3,5-triphenylbenzene tris-MIC ligand. Study of the electronic properties and catalytic activities

• Carmen Mejuto,
• Beatriz Royo,
• Gregorio Guisado-Barrios and
• Eduardo Peris

Beilstein J. Org. Chem. 2015, 11, 2584–2590, doi:10.3762/bjoc.11.278

• obtaining a series of Rh(I), Ir(I) and Ni(II) complexes. Interestingly, the tris-MIC complex of Ni is the first trimetallic Ni complex with a tris-carbene ligand. The electron-donating properties of the ligand were assessed by cyclic voltammetry and by IR spectroscopy of the corresponding carbonylated tris

Half-sandwich nickel(II) complexes bearing 1,3-di(cycloalkyl)imidazol-2-ylidene ligands

• Johnathon Yau,
• Kaarel E. Hunt,
• Laura McDougall,
• Alan R. Kennedy and
• David J. Nelson

Beilstein J. Org. Chem. 2015, 11, 2171–2178, doi:10.3762/bjoc.11.235

• reactivity, and to prepare and evaluate bis(ICy) complexes in catalysis. Conclusion We have prepared two new half-sandwich Ni(II) complexes, which until recently had been missing relatives in this practical and useful family of pre-catalysts. X-ray crystallographic analyses suggest a tendency towards η1,η4

(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

• -methylphenylalanines as well (Scheme 5). Towards this, the (S)-configured glycine nickel(II) complex (S)-10 was alkylated with 1-phenylethyl iodide and some analogues with substituents in the aryl moiety, all in racemic form. The diastereomeric product Ni(II) complexes obtained in each case, could be separated by

Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)amino]acetyl}amino)benzophenone; a case of configurationally stable stereogenic nitrogen

• Hiroki Moriwaki,
• Daniel Resch,
• Hengguang Li,
• Iwao Ojima,
• Ryosuke Takeda,
• José Luis Aceña and
• Vadim A. Soloshonok

Beilstein J. Org. Chem. 2014, 10, 442–448, doi:10.3762/bjoc.10.41

• observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements. Keywords: amino acids; asymmetric synthesis; Ni(II) complexes; Schiff bases; stereogenic nitrogen; Introduction

• novel and advanced structural type of Ni(II) complexes using an inexpensive and nonracemizable chiral auxiliary. As the first step in this direction, here we describe the preparation of Ni(II) complexes of glycine Schiff base with α-phenylethylamine-derived ligands. One unusual feature of these new

• glycine-Ni(II) complexes is that they, along with the chiral amine residue, have a configurationally stable stereogenic nitrogen, leading to formation of two diastereomers. Consequently, stereochemical assignments of the diastereomeric products, based on crystallographic data, and sense of stereochemical

Design and synthesis of quasi-diastereomeric molecules with unchanging central, regenerating axial and switchable helical chirality via cleavage and formation of Ni(II)–O and Ni(II)–N coordination bonds

• Vadim A. Soloshonok,
• José Luis Aceña,
• Hisanori Ueki and
• Jianlin Han

Beilstein J. Org. Chem. 2012, 8, 1920–1928, doi:10.3762/bjoc.8.223

• corresponding Ni(II) complexes, the formation of quasi-diastereomeric products is highly stereoselective providing formation of only two, (Ra*,Mh*,Rc*) and (Ra*,Ph*,Rc*), out of the four possible stereochemical combinations. The reversible quasi-diastereomeric transformation between the products (Ra*,Mh*,Rc

• spectra of compounds 14 and 15, resonances of aromatic and aliphatic hydrogens and carbons appear as sharp peaks indicating that the extra bidentate moiety in complexes 14 and 15 acts merely as a substituent and does not compete for coordination with Ni(II). Complexes 14 are red-colored, 15 is yellow, and

• asymmetric carbonyl/imine ligands 13 (Scheme 3) and Ni(II). In contrast to typical Ni(II) complexes, such as 14a,b, compounds 19/20 display an unusual dark-brown color. Nevertheless, their high solubility in polar organic solvents allows for their straightforward purification by column chromatography