Reactivity in the gas phase. Behaviour of isoxazoles under negative ion chemical ionization conditions

[M ? H⁺]^? ions of isoxazole (la), 3-methylisoxazole (1b), 5-methylisoxazole (1c), 5-phenylisoxazole (1d) and benzoylacetonitrile (2a) are generated using NICI/OH^? or NICI/NH₂^? techniques. Their fragmentation pathways are rationalized on the basis of collision-induced dissociation and mass-analysed ion kinetic energy spectra and by deuterium labelling studies. 5-Substituted isoxazoles 1c and 1d, after selective deprotonation at position 3, mainly undergo N ? O bond cleavage to the stable α-cyanoenolate NC ? CH ? CR ? O^? (R = Me, Ph) that fragments by loss of R? CN, or R? H, or H₂O. The same α-cyanoenolate anion (R = Ph) is obtained from 2a with OH^?, or NH₂^?, confirming the structure assigned to the [M ? H⁺]^? ion of 1d, On the contrary, 1b is deprotonated mainly at position 5 leading, via N? O and C(3)? C(4) bond cleavages, to H? C ≡ C? O ^? and CH₃CN. Isoxazole (1a) undergoes deprotonation at either position and subsequent fragmentations. Deuterium labelling revealed an extensive exchange between the hydrogen atoms in the ortho position of the phenyl group and the deuterium atom in the α-cyanenolate NC ? CD = CPh ? O^?.     

Insertion of N-sulfinylsulfonamides and bis(methylsulfonyl)sulfur diimide into ironcarbon σ bonds

The N-sulfinylsulfonamides R′S(O)₂NSO (R′ = CH₃, p-CH₃C₆H₄) insert into the FeR bonds of η⁵-C₅H₅Fe(CO)₂R (R = CH₃, CH₂C₆H₅) to afford η⁵-C₅H₅Fe(CO)₂N[S(O)₂R′][S(O)R]. These products undergo oxidation by m-ClC₆H₄C(O)-OOH to η⁵-C₅H₅Fe(CO)₂N[S(O)₂R′][S(O)₂R] and rearrange on storage to η⁵-C₅H₅Fe(CO)₂S(O)[NS(O)₂R′]R. Reaction between the η⁵-C₅H₅Fe(CO)₂R and CH₃S(O)₂NSNS(O)₂CH₃ leads to the insertion products η⁵-C₅H₅Fe(CO)₂N-[S(O)₂CH₃][S(R)NS(O)₂CH₃].     

Molybdenum and tungsten complexes with the heteroallyl-like Ph2P(O)C(S)NR− (R  Me,Ph) as ligand. X-ray structural analysis of Mo(CO)2(PPh3)(Ph2P(O)C(S)NPh)2 · CH2Cl2; A 4 : 3 piano-stool configuration

Ph₂P(O)C(S)N(H)R (R  Me, Ph) reacts with M(CO)₃(η⁵-C₅H₅)Cl (M  Mo, W) in the presence of Et₃N to give M(CO)₂(η⁵-C₅H₅)(Ph₂P(O)C(S)NR). The deprotonated ligand coordinates in a bidentate manner through N and S to give a four-membered ring system. M(CO)₃(PPh₃)₂Cl₂ (M  Mo, W) reacts with Ph₂P(O)C(S)N(H)R (R  Me, Ph) in the presence of Et₃N to give complexes in which the central metal atoms are seven coordinate through two ligands bonded via O and S to form five-membered ring systems, one PPh₃, and two CO groups. The complexes were characterised by elemental analyses, IR, ¹H NMR, and ³¹P NMR spectroscopy, and an X-ray structural analysis of Mo(CO)₂(PPh₃)(Ph₂P(O)C(S)NPh)₂ · CH₂Cl₂.     

The octant rule. XIV. synthesis and circular dichroism of α-exo and endo-deuteriobicyclo[3.2.1]octan-3-one and 6,6-dimethybicyclo[3.1.1]heptan-3-one

(1R,5S)-2S-Deuteriobicyclo[3.2.1]octan-3-one ($\text{1}$) and (1R,5S)-2R-Deuteriobicyclo[3.2.1]octan-3-one ($\text{2}$), prepared by diazomethane ring enlargement of (1S,4R)-2(exo)-deuteriobicyclo-[2.2.1] heptan-2-one and (1S,4R)-2(endo)-deuteriobicyclo[2.2.1]heptan-2-one respectively, both gave (?) n-π^* circular dichroism (CD) Cotton effects, Δε^max₂₉₄ = ?0.05 and Δε^max₂₉₄=?0.1, respectively, in hydrocarbon solvent. (1S,5R)-2S-Deuterio-6,6-diaethylbicyclo[3.1.1] heptan-3-one ($\text{3}$) and (1S,5R)-2R-deuterio-6,6-dimethylbicyclo[3.1.1] heptan-3-one ($\text{4}$), prepared from (-) myrtenal, both exhibited extraordinary vibrational fine structure for the n-π^* CD transitions observed in hydrocarbon solvent and oppositely?signed CEs, Δε^max₂₈₂=?0.01 and Δε^max₂₇₉=+0.01 respectively in CF₃CH₂OH solvent.     

SILYL- AND GERMYL-DIAZADIPHOSPHETIDINES

Abstract

Reaction of the 1,3,2,4-diazadiphosphetidine, trans-[C₆H₅N(H)P(S)NC₆H₅]₂ with LiR (R = Me, n-Bu) followed by treatment of the resulting dianions with Me₃SiCl and Me₃GeBr produced trans-[C₆H₅N(R)P(S)NC₆H₅]₂(R = Me₃Si, 2; Me₃Ge, 3). Substitution occurs without cis-trans isomerization or significant cleavage of the 1,3,2,4-diazadiphosphetidine ring. 2 and 3 have been characterized by spectral (¹H and ³¹P NMR, IR, and MS) and elemental analytical data. Analogous reactions involving Me₃SnCl yield mixtures containing [C₆H₅N(SnMe₃)P(S)NC₆H₅]₂ which could not be isolated or completely characterized.     

Zur Synthese gemischt substituierter Schwefeldiimide

Synthesis of mixed substituted sulfurdiimides Sulfurdiimides R? N?S?N? R ( 1 ) (R ? tBu or Me₃Si) react with potassium amide via transiminating forming the potassium salts R? N?S?N)^?K⁺ ( 2 ). Methatetical reactions of 2 with chlorides Me₃SnCl or Me₂SnCl₂ leads to the formation of the mixed subst. sulfurdiimides R? N?S?N? SnMe₃ ( 4 ) and (R? N?S?N)₂SnMe₂ ( 5 ), respectively.     

Neutral Hexacoordinate Phosphorus: Substituted Carbodiimide Phosphoranes and Other Chelated Substituted 2-Pyridine Derivatives

Abstract

A series of neutral hexacoordinate λ⁶ phosphorus compounds of the general formula X_4-n(CF₃)_nPN(R)C(C1)N(R) (n = 0, 1, 2, 3; R = cyclohexyl, isopropyl) has been prepared. The parent compounds are obtained by “insertion” of carbodiimide into the P-C1 bond of λ⁵-chlorophosphorane. Substituted pyridines also react readily with λ⁵ chloro and fluoro phosphoranes to form 2-methylamino, thio and oxopyridine chelates of the form X₄P(Epy) (E = 0, NMe and S; X = F, Cl) in which the phosphorus achieves six coordination through acceptance of the pyridine nitrogen. Selected reactions and the fluxional behavior of the λ⁶ systems are discussed.     

Synthesis and Characterization of New 1-Methyl-4-(Methylamino)Piperidine and Decahydroquinoline Platinum(II) Complexes Containing Disubstituted Sulfide as a Leaving Group

A series of cationic platinum(II) complexes of the type [Pt(mmap)R'R"S)Cl](NO₃) and [Pt(dhq)₂(R'R"S)Cl]-(NO₃) (where mmap=1-methyl-4-(methylamino)piperidine; dhq=decahydroquinoline; and R'R"S=dimethylsulfide, diethylsulfide, diisopropylsulfide, diphenylsulfide, dibenzylsulfide, methylphenylsulfide or methyl-p-tolylsulfide) has been synthesized and characterized by elemental analysis, infrared, ¹H and ¹⁹⁵Pt nuclear magnetic resonance spectroscopic techniques.     

Chalcogen–acetylide interaction and unusual reactivity of coordinated acetylide with water: synthesis and characterisation of [(η5-C5R5)Fe3(CO)6(μ3-E)(μ3-ECCH2RI)] (R=H,Me; RI=Ph,Fc; E=S,Se) and [(η5-C5R5)MoFe2(CO)6(μ3-S)(μ-SCCH2Ph)] (R=H,Me)

Photolysis of a benzene solution containing [Fe₃(CO)₉(μ₃-E)₂] (E=S, Se), [(η⁵-C₅R₅)Fe(CO)₂(CCR^I)] (R=H, Me; R^I=Ph, Fc), H₂O and Et₃N results in formation of new metal clusters [(η⁵-C₅R₅)Fe₃(CO)₆(μ₃-E)(μ₃-ECCH₂R^I)] (R=H, R^I=Ph, E=S 1 or Se 2; R=Me, R^I=Ph, E=S 3 or Se 4; R=H, R^I=Fc, E=S 5; R=Me, R^I=Fc, E=S 6 or Se 7). Reaction of [Fe₃(CO)₉(μ₃-S)₂]with [(η⁵-C₅R₅)Mo(CO)₃(CCPh)] (R=H, Me), under same conditions, produces mixed-metal clusters [(η⁵-C₅R₅)MoFe₂(CO)₆(μ₃-S)(μ-SCCH₂Ph)] (R=H 8; R=Me 9). Compounds 1–9 have been characterised by IR and ¹H and ¹³C-NMR spectroscopy. Structures of 1, 5 and 9 have been established crystallographically. A common feature in all these products is the formation of new C-chalcogen bond to give rise to a (ECCH₂R^I) ligand.     

Synthesis and Characterization of Novel Chiral (1R,2R)-1,2-Bis[5-(Aminomethylphospinic Acid)-1,3,4-Thiadiazol-2-YL]Ethane-1,2-Diols

Abstract

(1R,2R)-1,2-bis[5-(arylideneamino)-1,3,4-thiadiazol-2-yl]ethane-1,2-diol (2a–d) were synthesized by using appropriate aldehydes and (1R,2R)-1,2-bis(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (1) as a starting compound. Then, the phosphinic acid component (3a–d) were obtained from (2a–d) and hypophosporus acid. In addition, the structures of the novel chiral compounds (2a–d) and (3a–d) were confirmed by elemental analyses, IR, ¹H-NMR, ¹³C-NMR, and ³¹P-NMR spectra.

¹H NMR and ¹³C NMR spectra for 1, 2a, and 3a (Figures S1–S6) are available online in the Supplemental Materials.     

Synthesis and Characterization of New CIS-1,4-Diaminocyclohexane and Piperidine Platinum(II) Complexes Containing Disubstituted Sulfide Groups

Abstract

A series of cationic platinum(II) complexes of the type [Pt(cis-1,4-DACH)(R′R″S)Cl]NO₃ and [Pt(PIP)₂(R′R″S)Cl]NO₃ (where cis-1,4-DACH = cis-1,4-diaminocyclohexane; PIP = piperidine; and R′R″S = dimethylsulfide, diethylsulfide, dipropylsulfide, diisopropylsulfide, dibutylsulfide, diphenylsulfide, dibenzylsulfide, methylphenylsulfide, or methyl-p-tolylsulfide) have been synthesized and characterized by elemental analysis and infrared, ¹H, and ¹⁹⁵Pt nuclear magnetic resonance spectroscopy.     

üBER DIE INSERTION VON RPS2 IN DIE PN-BINDUNG VON AMINOPHOSPHINEN

Abstract

Aminophosphine des Typs R_n P(NR′₂)_3-n (n= 2, 1, 0; R = Ph, c-Hex, (-)Men, t-Bu; R′= Me, Et, n-Bu) reagieren mit 2, 4-Bis(aryl)-1, 3, 2, 4-dithiadiphosphetan-2, 4-disulfiden (ArPS₂)₂(Ar: Ph, 4-Methoxyphenyl = An, Naphthyl, Thienyl) unter formaler Insertion monomerer {ArPS₂)-Einheiten in eine oder in zwei der λ³-P—N-Bindung zu chiralen Organophosphorverbindungen Ar(R′₂N)P(S)—S—PR_n (NR′₂)_2-n(n = 2, 1, 0) und [Ar(R′₂N)P(S)—]₂PR₂(NR′₂)_1-n (n = 1.0). In diesen werden bei Raumtemperatur bevorzugt die λ³—P—N—und λ³—P—S-Bindungen durch H₂O oder Methanol unter Bildung von Produktgemischen solvolysiert. Mit Chlorwasserstoff bildet sich aus An(Et₂N)P(S)—S—PPh(NEt₂) das An(Et₂ N)P(S)—S—PPh(C1). Addition von Schwefel führt zu Ar(R′₂N)P(S)—S—P(S)R_n (NR′)_2-n (n=2, 1). Die Stereoisomerenbildung der neuen Verbindungen wird besprochen und ihre Struktur sowie die Zusammensetzung der Reaktionsmischungen aus den ³¹P-Spektren hergeleitet.

Aminophosphines R_n P(NR′₂)_3-n (n = 2, 1, 0; R = Ph. c-Hex, (-)Men, t-Bu; R′= Me, Et, n-Bu) react with 2, 4-Bis(aryl)-1, 3, 2, 4-dithiadiphosphetane-2, 4-disulfides (ArPS₂)₂ (Ar: Ph, 4-Methoxyphenyl = An, Naphthyl, Thienyl) under formal insertion of monomeric {ArPS₂)-units in one or in two of the λ³-P—N-bonds to yield chiral organophosphorus compounds Ar(R′₂N)P(S)—S—]₂PR_n (NR′₂)₂ (n = 2, 1, 0) and [Ar(R′₂N)P(S)—S—]₂ PR₂ (NR′₂)_2-n (n = 1, 0). At room temperature chiefly the A—P—N and A³—P—S-bonds in these products are solvolyzed by H, O or methanol with formation of mixtures of compounds. With hydrogen chloride An(Et₂N)P(S)—S—PPh(NEt₂) is converted into An(Et₂N)P(S)—S—PPh(Cl). Addition of sulfur yields Ar(R′₂N)P(S)—S P(S)R_n (NR′₂)_2-n (n = 2, 1). Stereoisomerism of the new compounds is discussed and their structures as well as the composition of reaction mixtures are deduced from “P-NMR-spectra”.     

Synthesis and Structure of Bis(2-Amino-5-Cyanopyridinium) Diaquadichlorocopper(II) Dichloride

The reaction of CuCl₂ with 2-amino-5-cyanopyridine and HCl in 1-propanol gave bis(2-amino-5-cyanopyridinium) diaquadichlorocopper(II) dichloride (1). Crystal data for 1 are: monoclinic, space group: P2₁/c, a = 8.461(3) Å, b=14.665(5) Å, c=7.883(3) Å, g =96.105(4)°, V=972.6(6) Å 3 , Z=2, D_calc =1.645 Mg/m³, w =1.691 mm^?1, F(OOO)=486, MoK _f( u =0.71073 Å), R1=0.0431 for [∣I∣ S 2 σ (I)] and R1=0.0680 for all 1944 unique reflections and 130 parameters. The structure exists as square planar Cu(H₂O)₂Cl₂ units with long semi-coordinate bonds to the cyano nitrogens of the 2-amino-5-cyanopyridinium ions. Hydrogen bonding from the water molecules and N―H hydrogens to the chloride irons stablises the lattice.     

Five-Membered Ruthenacycles: Ligand-Assisted Alkyne Insertion into 1,3-N,S-Chelated Ruthenium Borate Species

Building upon previous work, the chemistry of [(η⁶-p-cymene)Ru{P(OMe)₂OR}Cl₂], (R=H or Me) has been extended with [H₂B(mbz)₂]⁻ (mbz=2-mercaptobenzothiazolyl) using different Ru precursors and borate ligands. As a result, a series of 1,3-N,S-chelated ruthenium borate complexes, for example, [(κ²-N,S-L)PR₃Ru{κ³-H,S,S’−H₂B(L)₂}], ( 2 a – d and 2 a’ – d’ ; R=Ph, Cy, OMe or OPh and L=C₅H₄NS or C₇H₄NS₂) and [Ru{κ³-H,S,S’-H₂B(L)₂}₂], ( 3 : L=C₅H₄NS, 3’ : L=C₇H₄NS₂) were isolated upon treatment of [(η⁶-p-cymene)RuCl₂PR₃], 1 a – d (R=Ph, Cy, OMe or OPh) with [H₂B(mp)₂]⁻ or [H₂B(mbz)₂]⁻ ligands (mp=2-mercaptopyridyl). All the Ru borate complexes, 2 a – d and 2 a’ – d’ are stabilized by phosphine/phosphite and hemilabile N,S-chelating ligands. Treatment of these Ru borate species, 2 a’ – c’ with various terminal alkynes yielded two different types of five-membered ruthenacycle species, namely [PR₃{C₇H₄S₂-(E)-N-C=CH(R ’ )}Ru{κ³-H,S,S ’ −H₂B(L)₂}], ( 4 – 4’ ; R=Ph and R ’ =CO₂Me or C₆H₄NO₂; L=C₇H₄NS₂) and [PR₃{C₇H₄NS-(E)-S-C=CH(R ’ )}Ru{κ³-H,S,S ’ −H₂B(L)₂}], ( 5 – 5’ , 6 and 7 ; R=Ph, Cy or OMe and R ’ =CO₂Me or C₆H₄NO₂; L=C₇H₄NS₂). All these five-membered ruthenacycle species contain an exocyclic C=C moiety, presumably formed by the insertion of a terminal alkyne into the Ru−N and Ru−S bonds. The new species have been characterized spectroscopically and the structures were further confirmed by single-crystal X-ray diffraction analysis. Theoretical studies and chemical-bonding analyses established that charge transfer occurs from phosphorus to ruthenium center following the trend PCy₃<PPh₃<P(OPh)₃<P(OMe)₃.     

Reactions of trans-Carbonyl(Chloro)-[Bis(Triphenylphosphine)]Rhodium(I) with Substituted Cyclopentadienyl Tricarbonyl Molybdenum Anions

Reactions of trans-carbonyl(chloro)[bis(triphenylphosphine)]rhodium(I): trans-ClRh(CO)(PPh₃)₂ with substituted cyclopentadienyl tricarbonyl molybdenum anions, [Mo(CO)₃(η ⁵ -C₅H₄R)]^? (R=H; COCH₃) in tetrahydrofuran (THF) at 55°C for 24 h yielded two monometallic complexes as by-products: [Rh(CO)(PPh₃)(η⁵-C₅H₄R)] (R = H (1a); COCH₃ (2a)) and two main heterobimetallic compounds: [RhMo(CO)₄(PPh₃)₂(η⁵-C₅H₄R)] (R = H (1b); COCH₃ (2b)). These compounds were characterized by elemental analysis, IR and ¹H NMR spectra. The molecular structure of (2a) was determined by X-ray diffraction.     

Darstellung und oxidative Derivatisierung von Dialkylthiophosphiten

Preparation and Oxidative Derivatisation of Phosphonothionic Esters The kind of the amine used influences decisively course and rate of the reaction of trialkyl phosphites, (RO)₃P (R = Me, Et, Ph) with H₂S in the presence of different amines (Et₃N, Et₂NH, Et₂NPh, pyridine). Phosphonothionic esters, (RO)₂P(S)H (R = Me, Et, Bu), are obtained in over 80% yield by using pyridine as base and an alkali alcoholate as catalyst. The oxidative derivatisation of phosphonothionic esters by means of CCI₄ and protic (4-nitrophenol, 2,4,5-trichlorophenol, ammonia, piperidine, phenylhydrazine) or anionic nucleophiles (F^?, NCS^?, NCO^?, CN^?, N₃^?) (Atherton-Todd reaction) yields thiophosphoric acid derivatives (RO)₂P(S)Nuc (R = Me, Et, Bu: Nuc = 4-nitrophenoxy, PhNHNH; R = Me, Et: Nuc = 2,4,5-trichlorophenoxy, F, NCS, N₃; R = Me: NH₂, C₅H₁₀N; R = Et: Nuc = CI, CN) and in some cases the dealkylated products (RO)P(Nuc)SO^? (R = Me; Nuc = CI, F, NCS, CN). The phosphazenes (EtO)₂P(S)? N = PPh₃ and (MeO)₂P(S)? N ? P(OEt)₃, up to now unknown in literature, were obtained by treating thiophosphoryl azides with PPh₃ or P(OEt)₃, resp.     

Three pairs of enantiomers bearing mitochondria‐targeted TPP+ groups as potential anti‐cancer agents

Six complexes with chiral Schiff‐base ligands containing TPP⁺ groups, [VO L ^R,R/^S,S](ClO₄)₂( 1 for RR, 2 for SS), [Ni L ^R,R/S,S](ClO₄)₂·C₂H₅OH ( 3 for RR, 4 for SS) and [CuL^R,R/S,S](ClO₄)₂·CHCl₃·CH₃CH₂OH ( 5 for RR, 6 for SS) ( L ^R,R/S,S = N,N′‐Bis{5‐[(triphenylphosphonium)‐methyl]salicylidine}‐(1R,2R/1S,2S)‐diphenylethane‐1,2‐diamine, were synthesized to serve as mitochondrion‐targeting anticancer drugs. The introduction of TPP⁺ group(s) might markedly influence the properties of complexes. Compounds 3 and 5 were structurally characterized by X‐ray crystallography. Complexes 1–6 could be moderate intercalating agents to CT‐DNA which is determined by several spectroscopy methods. DNA cleavage experiments revealed that all compounds could promote oxidative cleavage of pBR322 plasmid DNA in the presence of H₂O₂. MTT assay indicated 1–6 exhibited effective cytotoxicity on A549 and MCF‐7 cell lines. Notably, the IC₅₀ values of 5 (1.24 ± 0.33 μM) or 6 (1.47 ± 0.52 μM) were approximately 9–11 fold lower than that of cisplatin (IC₅₀ = 13.56 ± 0.88 μM) on A549 cells. 5 and 6 were picked for further study, which indicated that the cytotoxicity seems to result from multiple mechanisms of action, including effectively suppress the growth and proliferation of A549 cells, generation of reactive oxygen species, dissipation of mitochondrial membrane potential, cell cycle perturbation and apoptosis induction. Compounds 1–6 could highly accumulate in the mitochondria by means of ICP‐MS assay. This study demonstrates that 1–6 with mitochondrion‐targeting function could be efficient anticancer drugs.     

Preparation of (1R∗,2S∗,5R∗,6R∗)-1-Methyl-2,5,6-Tribromo-Cyclooctane and 3-Methyl-6,7-Dibromocyclooctene

Abstract

Reaction of 4,5-dibromobicyclo[6.1.0]non-4-ene with anhydrous AlBr₃ forms (1R?,2S?,5R?,6R?)-1-methyl-2,5,6-tribromocyclooctane and 3-methyl-6,7-dibromocyclooctene.

     

π-Cyclopentadienyls of nickel(II) : XIII. The preparation and properties of the compounds π-C5H5NiPBu3SC(S)X (X = OR,R and NRH) and π-C5H5NiPBu3SC(O)NRH

Compounds of the type π-C₅H₅NiPBu₃SC(S)X (X = R, OR and NRH) are obtained from reactions between [π-C₅H₅Ni(PBu₃)₂]⁺Cl^? and SC(S)X^? in aqueous solution. Compounds such as π-C₅H₅NiPBu₃SC(S)NRH are also obtained by reactions of π-C₅H₅NiPBu₃SH with RNCS.Reactions of C₆H₅NCS with π-C₅H₅NiPBu₃SEt or [π-C₅H₅NiPBu₃S(CH₂)_n]₂ (n = 1, 2 and 3) give π-C₅H₅NiPBu₃[SC(NC₆H₅)SC₂H₅] or [π-C₅H₅NiPBu₃ {SC(NC₆H₅)S(CH₂)_n}]₂ respectively.Similar reactions of π-C₅H₅NiPBu₃SH and RNCO given π-C₅H₅NiPBu₃SC(O)NRH.Treatment of π-C₅H₅NiPBu₃SC(S)R with HCl gives π-C₅H₅NiSC(S)R.     

Efficient dehydration of primary amides to nitriles catalyzed by phosphorus-chalcogen chelated iron hydrides

A series of phosphorus-chalcogen chelated hydrido iron (II) complexes 1–7 , (o-(R'₂P)-p-R-C₆H₄Y)FeH (PMe₃)₃ ( 1 : R = H, R' = Ph, Y = O; 2 : R = Me, R' = Ph, Y = O; 3 : R = H, R' = ⁱPr, Y = O; 4 : R = Me, R' = ⁱPr, Y = O; 5 : R = H, R' = Ph, Y = S; 6 : R = Me, R' = Ph, Y = S; 7 : R = H, R' = Ph, Y = Se), were synthesized. The catalytic performances of 1–7 for dehydration of amides to nitriles were explored by comparing three factors: (1) different chalcogen coordination atoms Y; (2) R' group of the phosphine moiety; (3) R substituent group at the phenyl ring. It is confirmed that 5 with S as coordination atom has the best catalytic activity and 7 with Se as coordination atom has the poorest catalytic activity among complexes 1 , 5 and 7 . Electron-rich complex 4 is the best catalyst among the seven complexes and the dehydration reaction was completed by using 2 mol% catalyst loading at 60 °C with 24 hr in the presence of (EtO)₃SiH in THF. Catalyst 4 has good tolerance to many functional groups. Among the seven iron complexes, new complexes 3 and 4 were obtained via the O-H bond activation of the preligands o-ⁱPr₂P(C₆H₄)OH and o-ⁱPr₂P-p-Me-(C₆H₄)OH by Fe(PMe₃)₄. Both 3 and 4 were characterized by spectroscopic methods and X-ray diffraction analysis. The catalytic mechanism was experimentally studied and also proposed.