Antitumor effects of binuclear ferrocene derivatives

On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of the mono-, bi- and poly-nuclear ferrocene derivatives ferricenium tri-iodide (1), ferricenium tetrachloroferrate (2), 1, 1′-diethylferricenium triiodide: (3), N-(ferrocenylmethyl)hexamethylenetetramine tetrafluoroborate (4), bis(ferrocenylmethyl)benzotriazolium tetrafluoroborate (5), bis(ferrocenyl-α-ethyl)benzotriazolium tetrafluoroborate (6) and bis(ferrocenylmethyl)-2-methylbenzimidazolium tetrafluoroborate (7), and the oligomer (—Fc—CH₂—Fc^+˙—CH₂—)_7–8^? (PF₆)_7–8 (8) was studied in vivo (Fc?C₁₀H₈Fe). The tumor models studied included MCH-11 (mouse sarcoma induced by methylcholantrene), P-815 (mouse mastocytoma of DBA/2 origin) and virus-induced Raucher leukemia (RLV). The cytotoxic effects of these preparations were examined against in vitro cultured normal murine cells (line L-929). The binuclear ferrocene derivatives 5, 6 and 7 inhibited the development of experimental tumors in mice. Ferricenium tri-iodide (1) was effective in Rauscher leukemia. Kinetic dependencies for most complexes had a two-phase character: the region of inhibition of tumorogenesis was followed by a region in which the complexes accelerated the development of this process. The link between the structure of compounds 1–8 and their antitumor effects is discussed.     

One‐pot acid‐free ferrocenylalkylation of azoles with α‐ferrocenyl alcohols: ferrocene‐based plant growth regulators and herbicide safeners

α‐Ferrocenylalkylation of azoles or S‐nucleophiles with FcCH(R)OH (Fc = ferrocenyl) can be accomplished under acid‐free conditions as one‐pot process via an intermediate formation of the α‐ferrocenylalkyl carbonates FcCH(R)OC(O)OEt. The reaction allows the alkylation of acid sensitive substrates like imidazole derivatives or sodium N,N‐diethyldithiocarbamate. The reaction with ambident azoles proceeds as the N‐alkylation. Some α‐ferrocenylalkyl azoles were found to exhibit plant growth stimulating or herbicidal effects on corn seeds or act as the herbicide safeners against sulfonylurea herbicides.     

Synthesis, structure and redox potentials of biologically active ferrocenylalkyl azoles

The syntheses, structures, electrochemical properties of the series of ferrocenylalkyl azoles, FcAlkAz, as well as the antitumor activity of ferrocenylmethyl benzimidazole (8) have been studied. Above mentioned compounds were investigated by the method of cyclic voltametry. All of them exhibited a reversible one-electron oxidation-reduction wave owing to the ferrocene-ferrocenium redox couple with a positive shift (0.50-0.65 V) compared with that of ferrocene (0.42 V). The X-ray determination of molecular structures of 1-(ferrocenylmethyl)imidazole (4), 1-(ferrocenylbenzyl)imidazole (7) and 1-(ferrocenylmethyl)bezimidazole (8) was carried out. Compound 4 with imidazolyl substituent was found to be present in N-protonated form. Antitumor activity of 1-(ferrocenylmethyl)benzimidazole (8) against some solid tumor models such as adenocarcinoma 755 (Ca755), melanoma B16 (B16) and Lewis lung carcinoma was studied. The antitumor activity of compound 8 was compared with cisplatin effectiveness against some experimental tumor systems.     

The mono- and bis-(trichloroacetic acid)-solvates of ferricenium trichloroacetate

Summary Inconsistent literature reports on the preparation of the mono- and bis-(trichloroacetic acid)-solvated ferricenium trichloroacetates, (1) and (2) have prompted a comprehensive investigation of the experimental conditions giving rise to the formation of the two ferricenium salts. In agreement with the majority of authors, (2) is reproducibly obtained from trichloroacetic acid and ferrocene in molar ratios of 3 and higher in benzene over a wide range of experimental variables in the presence of air or, preferably, under conditions of oxygen saturation. Treatment of aqueous ferricenium sulfate solutions with trichloroacetic acid in an acid/ferrocene ratio of 3 and above affords the di-solvate, whereas at lower reactant ratios, and under conditions of reduced acidity, formation of the mono-solvate prevails. More efficiently, and in a higher degree of purity, the latter salt is generated from the former by a controlled recrystallization from water. Representative spectroscopic features of the two salts are discussed.     

Solid-state interaction of trimethylammonioalkylferrocene iodides with primary amines

The syntheses of several aminoalkylferrocenes by the solid-state reactions of trimethylammoniomethylferrocene iodides and (S)-(–)-(1-trimethylammonio)ethylferrocene with primary amines are described. New ferrocenylalkylamines were synthesized: 1-(4-toluidino)ethylferrocene, 1-(2-pyridylamino)ethylferrocene, 2-pyridylaminomethylferrocene, and N,N-bis(ferrocenylmethyl)-2-pyridylamine.     

Development of a method to screen and isolate potential α‐glucosidase inhibitors from Panax japonicus C.A. Meyer by ultrafiltration,liquid chromatography,and counter‐current chromatography

A new assay based on ultrafiltration, liquid chromatography and mass spectrometry was developed for the rapid screening and identification of the ligands for α‐glucosidase from the extract of Panax japonicus. Six saponins were identified as α‐glucosidase inhibitors. Subsequently, the specific binding ligands, namely, notoginsenoside R₁, ginsenoside Rb₁, chikusetsusaponin V, chikusetsusaponin IV, chikusetsusaponin IVa, and ginsenoside Rd (the purities were 94.18, 95.43, 96.09, 93.26, 94.50, 93.86%, respectively) were separated by counter‐current chromatography using two‐phase solvent systems composed of tert‐butyl methyl ether, acetonitrile, 0.1% aqueous formic acid (3.8:1.0:4.4, v/v/v) and the solvent system composed of methylene chloride, isopropanol, methanol, 0.1% aqueous formic acid (5.8:1.0:6.0:2.2, v/v/v). The results demonstrate that ultrafiltration, liquid chromatography and mass spectrometry combined with high‐speed counter‐current chromatography might provide not only a powerful tool for screening and isolating α‐glucosidase inhibitors in complex samples but also a useful platform for discovering bioactive compounds for the prevention and treatment of diabetes mellitus.     

Cationic Ir/Me‐BIPAM‐Catalyzed Asymmetric Intramolecular Direct Hydroarylation of α‐Ketoamides

Asymmetric intramolecular direct hydroarylation of α‐ketoamides gives various types of optically active 3‐substituted 3‐hydroxy‐2‐oxindoles in high yields with complete regioselectivity and high enantioselectivities (84–98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod)₂](BAr^F₄) and the chiral O‐linked bidentate phosphoramidite (R,R)‐Me‐BIPAM.     

α‐Amino acid: an effective ligand for asymmetric catalysis of transfer hydrogenation of ketones

Ruthenium complexes, prepared by mixing the potassium salt of α‐amino acids and [RuCl₂(arene)]₂, acted as catalysts for the asymmetric transfer hydrogenation of ketones from 2‐propanol in the presence of KOH. For example, the transfer hydrogenation of acetophenone from 2‐propanol was catalyzed effectively by the ruthenium complex prepared from potassium L ‐prolinate and [RuCl₂(p‐cymene)]₂ to give (R)‐1‐phenylethanol in 72% yield with 81% ee. The yields and enantioselectivities of the product were influenced strongly by the structure of the α‐amino acidate ligand, arene ligand, and substrate, by the amount of additional base, and by the concentration of the substrates. The best enantiomeric excesses of the products was 92%, when 1‐tetralone was subjected to this reaction using a prolinated ruthenium complex bearing p‐cymene. Furthermore, the potassium salts of dipeptides were tested as a ligand for this transfer hydrogenation. Copyright © 2001 John Wiley & Sons, Ltd.     

Synthesis and some Reactions of Alkali Metal Carbamotelluroates

Sodium and potassium carbamotelluroates [M(R₂NCOTe), M = Na, K, Rb, Cs] were synthesized in moderate to good yields by reacting carbamoyl chloride with the corresponding alkali metal tellurides. The salts readily reacted with trimethylsilyl chloride to form O‐trimethylsilyl carbamotelluroate (R₂NCTeOSiMe₃), which further reacted with RbF and CsF to lead to the corresponding heavy alkali metal carbamotelluroates. These salts reacted with alkyl iodide and carbamoyl chlorides to give the corresponding Te‐alkyl carbamotelluroates and dicarbamoyl tellurides in moderate yields.     

Large‐scale separation of antipsychotic alkaloids from Rauwolfia tetraphylla L. by pH‐zone‐refining fast centrifugal partition chromatography

pH‐zone‐refining centrifugal partition chromatography was successively applied in the large‐scale separation of close R_f antipsychotic indole alkaloids directly from CHCl₃ fraction of Rauwolfia tetraphylla leaves. Two experiments with increasing mass from 500 mg to 3 g of crude alkaloid extracts ( 1 C) of R. tetraphylla were carried out in normal‐displacement mode using a two‐phase solvent system composed of methyl tert‐butyl ether/ACN/water (4:1:5, v/v/v) where HCl (12 mM) was added to the lower aqueous stationary phase as a retainer and triethylamine (5 mM) to the organic mobile phase as an eluter. The two centrifugal partition chromatography separations afforded a total of 162.6 mg of 10‐methoxytetrahydroalstonine ( 1 ) and 296.5 mg of isoreserpiline ( 2 ) in 97% and 95.5% purity, respectively, along with a 400.9 mg mixture of α‐yohimbine and reserpiline ( 3 and 4 ). Further, this mixture was resolved over medium pressure LC using TLC grade silica gel H (average particle size 10 μm), which afforded 160.4 mg of α‐yohimbine ( 3) and 150.2 mg of reserpiline ( 4) in >95% purities. The purity of the isolated antipsychotic alkaloids was analyzed by high‐performance LC and their structures were characterized on the basis of their 1D, 2D NMR and electrospray ionization‐mass spectroscopic data.     

α‐Propargyl amino acid‐derived optically active novel substituted polyacetylenes: Synthesis,secondary structures,and responsiveness to ions

Novel optically active substituted acetylenes HC? CCH₂CR¹(CO₂CH₃)NHR² [(S)‐/(R)‐ 1 : R¹ = H, R² = Boc, (S)‐ 2 : R¹ = CH₃, R² = Boc, (S)‐ 3 : R¹ = H, R² = Fmoc, (S)‐ 4 : R¹ = CH₃, R² = Fmoc (Boc = tert‐butoxycarbonyl, Fmoc = 9‐fluorenylmethoxycarbonyl)] were synthesized from α‐propargylglycine and α‐propargylalanine, and polymerized with a rhodium catalyst to provide the polymers with number‐average molecular weights of 2400–38,900 in good yields. Polarimetric, circular dichroism (CD), and UV–vis spectroscopic analyses indicated that poly[(S)‐ 1 ], poly[(R)‐ 1 ], and poly[(S)‐ 4 ] formed predominantly one‐handed helical structures both in polar and nonpolar solvents. Poly[(S)‐ 1a ] carrying unprotected carboxy groups was obtained by alkaline hydrolysis of poly[(S)‐ 1 ], and poly[(S)‐ 4b ] carrying unprotected amino groups was obtained by removal of Fmoc groups of poly[(S)‐ 4 ] using piperidine. Poly[(S)‐ 1a ] and poly[(S)‐ 4b ] also exhibited clear CD signals, which were different from those of the precursors, poly[(S)‐ 1 ] and poly[(S)‐ 4 ]. The solution‐state IR measurement revealed the presence of intramolecular hydrogen bonding between the carbamate groups of poly[(S)‐ 1 ] and poly[(S)‐ 1a ]. The plus CD signal of poly[(S)‐ 1a ] turned into minus one on addition of alkali hydroxides and tetrabutylammonium fluoride, accompanying the red‐shift of λ_max. The degree of λ_max shift became large as the size of cation of the additive. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Evaluation of the activity of some water-soluble ferrocene and ferricenium compounds against carcinoma of the lung by the human tumor clonogenic assay

The two ferrocene compounds, ferrocenylacetic acid (3) and ferrocylthiomalic acid (4), as well as the ferricenium salts, ferricenium tetrachloroferrate (III) (1) and ferricenium trichloroacetate–trichloroacetic acid solvate (2), were investigated by the in vitro human tumor clonogenic assay for their inhibiting effects, in continuous exposure in a double-layer medium, on the colony formation of single-cell suspensions prepared from 30 selected fresh specimens of human adenocarcinoma, squamous cell carcinoma and large-cell carcinoma of the lung. At the high drug concentration level of 100 μg cm ^?3, good response ratios were observed for 3 (79%) and 4 (72%), followed by 1 (67%) and 2 (52%). At the low concentration level of 10 μg cm^?3 response ratios were below 25% for all compounds, best performance (24%) being shown by 1. In vitro experiments probing the schedule dependencies of the compounds' inhibiting effects against the lung carcinoma cell line PC-9 were also performed, as were experiments involving the combination of the ferricenium salt 1 and cisplatin, which showed the combination effect to be additive in both one-hour and continuous-exposure tests.     

Ethylene/α‐olefin copolymerization with bis(β‐enaminoketonato) titanium complexes activated with modified methylaluminoxane

Copolymerizations of ethylene with α‐olefins (i.e., 1‐hexene, 1‐octene, allylbenzene, and 4‐phenyl‐1‐butene) using the bis(β‐enaminoketonato) titanium complexes [(Ph)NC(R₂)CHC(R₁)O]₂TiCl₂ ( 1a : R₁ = CF₃, R₂ = CH₃; 1b : R₁ = Ph, R₂ = CF₃; and 1c : R₁ = t‐Bu, R₂ = CF₃), activated with modified methylaluminoxane as a cocatalyst, have been investigated. The catalyst activity, comonomer incorporation, and molecular weight, and molecular weight distribution of the polymers produced can be controlled over a wide range by the variation of the catalyst structure, α‐olefin, and reaction parameters such as the comonomer feed concentration. The substituents R₁ and R₂ of the ligands affect considerably both the catalyst activity and comonomer incorporation. Precatalyst 1a exhibits high catalytic activity and produces high‐molecular‐weight copolymers with high α‐olefin insertion. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6323–6330, 2005     

A new P,S‐coordinating ferrocenyl ligand: synthesis of a precursor and its coordination compounds with PdII and PtII

In our ongoing development of ferrocene ligands, 1‐dimethylamino‐2‐(diphenylphosphinothioyl)ferrocene is being used as a convenient building block to obtain racemic or enantiomerically pure ligands. Using this building block in large excess allowed the formation of several by‐products, two of which have already been reported; the structure of a third by‐product, namely 1‐(diphenylphosphinothioyl)‐2‐{[(diphenylphosphinothioyl)sulfanyl]methyl}ferrocene, [Fe(C₅H₅)(C₃₀H₂₅P₂S₃)], is presented here. The crystal structure is built up from a ferrocene unit, with one of the cyclopentadienyl (Cp) rings substituted in the 1‐ and 2‐positions by a protected diphenylphosphinothioyl group and a [(diphenylphosphinothioyl)sulfanyl]methyl fragment, –CH₂SP(=S)Ph₂. There are C—H...S interactions which result in the formation of chains parallel to the c axis. After desulfurization, the crude material was then reacted with Pd and Pt (M) precursors [MCl₂(CH₃CN)₂] to yield two isostructural dinuclear complexes arranged around twofold axes, namely (R,R/S,S)‐bis{μ‐[2‐(diphenylphosphanyl)ferrocen‐1‐yl]methanethiolato‐κ³P,S:S}bis[chloridopalladium(II)] pentane disolvate, [Pd₂{Fe(C₅H₅)(C₁₈H₁₅PS)}₂Cl₂]·2C₅H₁₂, and the platinum(II) analogue, (R,R/S,S)‐bis{μ‐[2‐(diphenylphosphanyl)ferrocen‐1‐yl]methanethiolato‐κ³P,S:S}bis[chloridoplatinum(II)] toluene monosolvate, [Pt₂{Fe(C₅H₅)(C₁₈H₁₅PS)}₂Cl₂]·C₇H₈, in which the two metal atoms present a slightly distorted square‐planar geometry formed by two bridging S atoms and P and Cl atoms. The P,S‐chelating ligand results from the rupture of one of the P—S bonds in the starting ligand. These dinuclear complexes display a butterfly geometry. Surprisingly, only the (R,R/S,S) diastereoisomer has been isolated.     

Trimethylsilylcyanation of heterocyclic imines catalysed by Lewis acids

The addition of Me₃SiCN to Schiff bases 1a–8a, synthesized by the reaction of furan and thiophene aldehydes with 3‐ and 4‐aminobenzotrifluorides, has been studied in the presence of various Lewis acids. A series of the corresponding trifluoromethyl derivatives of heterocyclic α‐aminonitriles 1–8 was synthesized in 38–80% isolated yields. It was found that 4A molecular sieves (MS) accelerate the addition and increase the yields of the products. The investigated catalysts are ranked by their activity in the following order: AlBr₃ + 4AMS > AlBr₃ > AlCl₃ > Ti[O(iPr)]₄. A single crystal of N‐(5‐methyl‐2‐thienylcyanomethyl)‐3‐trifluoromethylaniline was obtained and studied by X‐ray diffraction. The results showed that it was the crystal of the (R) isomer of this compound. Copyright © 2000 John Wiley & Sons, Ltd.     

Synthesis,crystal structure,electronic spectroscopy,electrochemistry and biological studies of carbohydrate containing ferrocene amides

A series of four new ferrocene–carbohydrate amides was prepared from pentose and hexose sugar derivatives. These include (5‐amino‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2a), (5‐amino‐3‐O‐benzyl‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2b), (methyl‐6‐amino‐6‐deoxy‐2,3‐O‐isopropylidene‐β‐d ‐ribofuranoside)‐1‐ferrocene carboxamide (2c) derived from furanose sugars and (6‐amino‐6‐deoxy‐1,2:3,4‐di‐O‐isopropylidene‐α‐d ‐galactopyranose)‐1‐ferrocene carboxamide (2d) derived from pyranose sugar. The compounds were characterized by spectroscopic means and the structure of amide derived from α‐d ‐xylofuranose (2a) was determined by X‐ray crystallography. The electronic and optical properties of the compounds were studied by means of cyclic voltammetry and absorption spectroscopy. The UV and electrochemical studies of these compounds, performed in aqueous solutions under physiological conditions (at pH 7.4), confirmed their stability. These results indicated that the compounds were suitable for conducting biological studies. The CD spectral analysis displays the effect of sugar substituents on the compounds. The cytotoxicity and antimicrobial activity of these conjugates were investigated on different cancer cell lines and microbes respectively. The degree of inhibition varied over a broad spectrum of Gram‐ positive and Gram‐negative bacteria. In addition, the compounds also exhibited antioxidant properties. Copyright © 2012 John Wiley & Sons, Ltd.     

Preferred 3D‐Structure of Peptides Rich in a Severely Conformationally Restricted Cyclopropane Analogue of Phenylalanine

Terminally blocked, homo‐peptide amides of (R,R)‐1‐amino‐2,3‐diphenylcyclopropane‐1‐carboxylic acid (c₃diPhe), a chiral member of the family of C^α‐tetrasubstituted α‐amino acids, from the dimer to the tetramer, and diastereomeric co‐oligopeptides of (R,R)‐ or (S,S)‐c₃diPhe with (S)‐alanine residues to the trimer level were prepared in solution and fully characterized. The synthetic effort was extended to terminally protected co‐oligopeptide esters to the hexamer, where c₃diPhe residues are combined with achiral α‐aminoisobutyric acid residues. The preferred conformations of the peptides were assessed in solution by FT‐IR absorption, NMR, and CD techniques, and for seven oligomers in the crystal state (by X‐ray diffraction) as well. This study clearly indicates that c₃diPhe, a sterically demanding cyclopropane analogue of phenylalanine, tends to fold peptides into β‐turn and 3₁₀‐helix conformations. However, when c₃diPhe is in combination with other chiral residues, the conformation preferred by the resulting peptides is also dictated by the chiral sequence of the amino acid building blocks. The (S,S)‐enantiomer of this α‐amino acid, unusually lacking asymmetry in the main chain, strongly favors the left‐handedness of the turn/helical peptides formed.     

Synthesis,pH‐ and temperature‐induced micellization and gelation of doubly hydrophilic triblock copolymer of poly(N,N‐dimethylamino‐2‐ethylmethacrylate)‐b‐poly(ethylene glycol)‐b‐poly(N,N‐dimethylamino‐2‐ethylmethacrylate) in aqueous solutions

A doubly hydrophilic triblock copolymer of poly(N,N‐dimethylamino‐2‐ethyl methacrylate)‐b‐Poly(ethylene glycol)‐b‐poly(N,N‐dimethylamino‐2‐ethylmethacrylate) (PDMAEMA‐b‐PEG‐b‐PDMAEMA) with well‐defined structure and narrow molecular weight distribution (M_w/M_n = 1.21) was synthesized in aqueous medium via atom transfer radical polymerization (ATRP) of N,N‐dimethylamino‐2‐ethylmethacrylate (DMAEMA) initiated by the PEG macroinitiator. The macroinitiator and triblock copolymer were characterized with ¹H NMR and gel permeation chromatography (GPC). Fluorescence spectroscopy, dynamic light scattering (DSL), transmittance measurement, and rheological characterization were applied to investigate pH‐ and temperature‐induced micellization in the dilute solution of 1 mg/mL when pH > 13 and gelation in the concentrated solution of 25 wt % at pH = 14 and temperatures beyond 80 °C. The unimer of R_h = 3.7 ± 0.8 nm coexisted with micelle of R_h = 45.6 ± 6.5 nm at pH 14. Phase separation occurred in dilute aqueous solution of the triblock copolymer of 1 mg/mL at about 50 °C. Large aggregates with R_h = 300–450 nm were formed after phase separation, which became even larger as R_h = 750–1000 nm with increasing temperature. The gelation temperature determined by rheology measurement was about 80 °C at pH 14 for the 25 wt % aqueous solution of the triblock copolymer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5869–5878, 2008     

Antineoplastic activity of polyaspartamide–ferrocene conjugates

The ferrocene/ferricenium redox system plays a significant role in biological oxidation, reduction and free-radical reactions. Of particular interest are the findings of earlier investigations which showed certain water-soluble ferricenium salts to possess appreciable antiproliferative activity against various murine tumor lines and a xenografted human colorectal adenocarcinoma. Solubility in water, a prerequisite for efficacious transport and dissipation in central circulation, was then proposed as a principal requirement for the ferrocene complex system to exert antineoplastic activity irrespective of the oxidation state in which it is administered. In order to shed more light on this question, we decided to investigate the antiproliferative properties of polymer–ferrocene conjugates containing the metal complex in the non-oxidized (ferrocene) form while fulfilling the critical requirement of water solubility. To this end, five selected, water-soluble conjugates, synthesized by reversible coupling of 4-ferrocenylbutanoic acid to variously structured polyaspartamides featuring pendant primary amino groups as coupling sites, were tested in vitro against cultured HeLa cells at concentrations up to 50 µg Fe ml⁻¹. Optimal antiproliferative activities, with IC₅₀ in the range of 2–7 µg Fe ml⁻¹, were determined for three compounds possessing tertiary-amine functions susceptible to protonation at physiological pH. Lower activities (IC₅₀ = 45–60 µg Fe ml⁻¹) were demonstrated for two poly(ethylene oxide)-containing conjugates. However, no reasonable structure–performance relationships can be derived at this stage from the small number of compounds tested. Copyright © 1998 John Wiley & Sons, Ltd.     

Aminoderivate von α‐P4S3, α‐P4Se3 und P3Se4 – Daten und Analyse der 31P‐NMR‐Spektren in Lösungen

Amino Derivatives of α‐P₄S₃, α‐P₄Se₃, and P₃Se₄; Data and Analyses of their ³¹P NMR Spectra in Solution α‐P₄S₃I₂, α‐P₄Se₃I₂, and P₃Se₄I were reacted with primary and secondary amines in CS₂. The reaction yields exo‐exo isomeres of α‐P₄S₃L₂ and α‐P₄Se₃L₂, the N‐bridged compounds α‐P₄S₃L′ and P₃Se₄L, with L = NHR¹, NPhR², THC (R¹ = ^tBu, Ad, Ph, Flu, TPMP; R² = Me, Et, ⁱPr), and L′ = NR¹. The ³¹P NMR data of the compounds in CS₂ solution were measured. By the reaction of α‐P₄Se₃I₂ with primary amines NH₂^tBu and NH₂Ad in CS₂ an asymmetric isomer α‐P₄Se₃I_endo(NHR¹)_exo was observed for the first time in the ³¹P NMR spectra. The influence of the ligands L on the ³¹P NMR parameter of α‐P₄S₃L₂, α‐P₄Se₃L₂, and P₃Se₄L is discussed.