Synthesis and antiosteoclast activity of Di(1‐oxo/thioxoperhydro‐1λ5‐[1,3,2] diazaphospholo [1,5‐a]pyridine‐1‐yl) (4‐substituted phenyl) boronates

A new family of di(1‐oxo/thioxoper‐hydro‐1λ⁵‐[1,3,2]diazaphospholo[1,5‐a]pyridine‐1‐yl)(4‐substituted phenyl) boronates ( 4a – j ) has been synthesized in a two‐step process. A reaction of (±)‐piperidin‐2‐yl‐methanamine ( 1 ) phosphoryl/phosphorothioyl chloride in the presence of triethylamine in dry tetrahydrofuran formed the intermediate monochloride ( 2 ), which on condensation with p‐substituted phenylboronic acids ( 3a – j ) afforded the titled compounds ( 4a – j ). They were characterized by elemental, IR, ¹H, ¹³C, ³¹P NMR, and mass spectral analyses. All these compounds showed moderate to high antiosteoclast and osteoblast activity. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:247–253, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21010     

Synthesis of Tricyclic (λ5)-Phosphoranes; unusual N-demethylation/N-alkylation reactions during the oxidative addition of hexafluoroacetone and tetrachloro-ortho-benzoquinone to benzodiaza-λ3-phosphorinones. Single crystal X-ray diffraction studies of various products

The reaction of methylisatoic acid anhydride 1 with benzylamines led to the N-benzyl-N′-methylanthranilamide derivatives 2 – 4 . Their reaction with phosphorus trichloride furnished the 2-chloro-1-halobenzyl/benzyl-3-methyl-4(1 H)-1,3,2-benzodiazaphosphorin-4-ones 5 – 7 which, upon reaction with bis-(2-chloroethyl)ammonium chloride/triethylamine, were converted into the P-bis-(2-chloroethyl)amino-1-halobenzyl/benzyl-3-methyl-4(1 H)-1,3,2-benzodiazaphosphorin-4-ones 8 – 10 and 12 . With 2-chloroethylammonium chloride/triethyl-amine the P? NHCH₂CH₂Cl-substituted compound 11 was obtained from the P^IIICl-species 6 . The reaction of 8 – 10 and 12 with hexafluoroacetone (HFA) took an unusual course: apart from the oxidative addition of HFA and formation of the perfluoropinacolyl ring system, one of the two CH₂CH₂Cl groups was found to alkylate the CH₃N atom with formation of a five-membered (diazaphospholane) ring in the tricyclic phosphoranes 13 – 16 . The reaction of 11 with HFA also produced a spirophosphorane 17 which involved a λ⁵-oxazaphosphetidine ring system. In the reaction of 8, 10 and 12 with tetrachloro-o-benzoquinone, an oxidative addition reaction with concomitant N-alkylation and formation of the tricyclic phosphoranes 18 – 20 was found to take place. Single crystal X-ray structure determinations are described for the phosphoranes 13, 14 and 16 , and for the precursor compound 9 . The following features are common to the isostructural compounds 13 and 16 and the diethyl ether hemisolvate of 14 : the (λ⁵)-spiro phosphorus atom lies out of the plane of the other atoms of the rings to which it is common, and the dioxaphospholane rings display a twist conformation. In the λ³P-compound 9 the phosphorus atom also lies out of the plane of the other ring atoms.     

Diastereo‐ and Enantioselective Intramolecular [2+2] Photocycloaddition Reactions of 3‐(ω′‐Alkenyl)‐ and 3‐(ω′‐Alkenyloxy)‐Substituted 5,6‐Dihydro‐1H‐pyridin‐2‐ones

3‐(ω′‐Alkenyl)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 2 – 4 were prepared as photocycloaddition precursors either by cross‐coupling from 3‐iodo‐5,6‐dihydro‐1H‐pyridin‐2‐one ( 8 ) or—more favorably—from the corresponding α‐(ω′‐alkenyl)‐substituted δ‐valerolactams 9 – 11 by a selenylation/elimination sequence (56–62 % overall yield). 3‐(ω′‐Alkenyloxy)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 5 and 6 were accessible in 43 and 37 % overall yield from 3‐diazopiperidin‐2‐one ( 15 ) by an α,α‐chloroselenylation reaction at the 3‐position followed by nucleophilic displacement of a chloride ion with an ω‐alkenolate and oxidative elimination of selenoxide. Upon irradiation at λ=254 nm, the precursor compounds underwent a clean intramolecular [2+2] photocycloaddition reaction. Substrates 2 and 5 , tethered by a two‐atom chain, exclusively delivered the respective crossed products 19 and 20 , and substrates 3 , 5 , and 6 , tethered by longer chains, gave the straight products 21 – 23 . The completely regio‐ and diastereoselective photocycloaddition reactions proceeded in 63–83 % yield. Irradiation in the presence of the chiral templates (?)‐ 1 and (+)‐ 31 at ?75 °C in toluene rendered the reactions enantioselective with selectivities varying between 40 and 85 % ee. Truncated template rac‐ 31 was prepared as a noranalogue of the well‐established template 1 in eight steps and 56 % yield from the Kemp triacid ( 24 ). Subsequent resolution delivered the enantiomerically pure templates (?)‐ 31 and (+)‐ 31 . The outcome of the reactions is compared to the results achieved with 4‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones and quinolones.     

Reaktionen von 5H-1,2λ5-Azaphospholen mit Arylazocarbonitrilen sowie Acetylendicarbonsäure-estern

Reactions of 5H,2λ⁵-Azaphospholes with Arylazocarbonitriles and Dialkyl Acetylenedicarboxylates Azaphospholes 1a – c react with activated arylazocarbonitriles to 1,5,2λ⁵-diazaphosphorines 2a – c and 3a – c . The reaction of 1a – c with diethyl or dimethyl acetylenedicarboxyiates yields 7H-1,4λ⁵-azaphosphepines 4a – c . The structures of 2b , 3a , and 4a are established by an X-ray diffraction analysis.     

Synthesis and Structure of O,O‐Diethyl N‐[(trans‐4‐Aryl‐5,5‐dimethyl‐2‐oxido‐2λ5‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates

A study on the synthesis of the novel N‐(cyclic phosphonate)‐substituted phosphoramidothioates, i.e., O,O‐diethyl N‐[(trans‐4‐aryl‐5,5‐dimethyl‐2‐oxido‐2λ⁵‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates 4a – l , from O,O‐diethyl phosphoramidothioate ( 1 ), a benzaldehyde or ketone 2 , and a 1,3,2‐dioxaphosphorinane 2‐oxide 3 was carried out (Scheme 1 and Table 1). Some of their stereoisomers were isolated, and their structure was established. The presence of acetyl chloride was essential for this reaction and accelerated the process of intramolecular dehydration of intermediate 5 forming the corresponding Schiff base 7 (Scheme 2).     

Synthese von Fluoro-λ5-monophosphazenen und Fluoro-1, 3-diaza-2λ5, 4λ5-diphosphetidinen mittels der Staudinger-Reaktion

Synthesis of Fluoro-λ⁵-monophosphazenes and Fluoro-1,3-diaza-2λ⁵,4λ⁵-diphosphetidines by Means of the Staudinger Reaction 35 Tetrafluoro- and 2 difluorodiaza-diphosphetidines as well as 4 difluoro- and 30 monofluoro-λ⁵-monophosphazenes were prepared by the Staudinger reaction between tervalent phosphorus fluorides, R_nPF_3?n (n = 1, 2; R = R₂N, (CH₂)₅N, O(CH₂)₄N, RO, (CH₂O)₂, alkyl, aryl) and phenylazides, X? C₆H₄N₃ (X = H, 4-CH₃, 4-Cl, 4-Br, 4-NO₂, 3-NO₂). PF₃ does not react with phenylazide The influence of substituents on the structure of the reaction products is discussed. Kinetic measurements allowed to determine the constants λ^P_I of the substituents (CH₂)₅N, O(CH₂)₄N and R(C₆H₅)N (R = CH₃, C₂H₅, n-C₄H₉).     

Die Reaktion von λ5-Diphospheten mit COS und CO2 Dihydro-λ5-Phosphete

Reactions of λ⁵-Diphosphetes with COS and CO₂. Dihydro-λ⁵-Phosphetes 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1 , reacts with COS to yield the (3-oxo-3,4-dihydro-1λ⁵-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 7 . Reaction of dimethyl substituted 1 , i.e. 1,1,3,3-tetrakis(dimethylamino)-2,4-dimethyl-1λ⁵,3λ⁵-diphosphete 4 , with COS and CO₂ results in (3-oxo-2,3-dihydro-1λ⁵-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 9 , and (3-oxo-2,3-dihydro-1λ⁵-phosphete-2-yl)-phosphonic bis(dimethylamide) 10 , respectively. Reaction mechanisms are suggested. 7, 9 and 10 are characterized by their properties, and their nmr, mass-, and ir-spectra. The results of X-ray structural analyses of 9 and 10 are reported and discussed.     

Facile syntheses and antimicrobial studies of 6‐(aryloxy/arylthio/chloroethoxy)‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloromemyl‐12H‐dibenzo[d,g][13,2]dioxaphosphocin 6‐oxides

Synthesis of several novel 6‐aryloxy/arylmio/chloroethoxy‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloro‐memyl‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides ( 4a‐k ) was accomplished by reacting 2,2‐bis (2‐hydroxy‐5‐chloro‐3‐nitrophenyl)‐1,1,1‐trichloroethane 2 with different aryl phosphorodichloridates ( 3a‐g ) and O‐2‐chloroethyl phosphoryldichloride ( 3h ) in the presence of triethylamine in dry toluene at 60–65 °C. Actually some of these compounds were prepared by reacting monochloride 5 resulting from the condensation of phosphorus oxychloride with 2 in situ, with different phenols and thiophenols. The chemical structures were confirmed by elemental, ir and ¹H, ¹³C, ³¹P nmr and mass spectral data analyses. These compounds were screened for antifungal activity against Aspergillus flavus, Alternaria alternata, Fusarium solani, Curvularia lunata and Pyricularia oryzae and antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas syringae and Klebsiella pneumoniae. Some of them possessed significant activity.     

Facile Synthesis of Substituted Ethyl 2‐(Chloromethyl)‐2‐hydroxy‐2H‐1‐benzopyran‐3‐carboxylates

Ethyl 2‐(chloromethyl)‐2‐hydroxy‐2H‐chromene‐3‐carboxylates 2a – 2j have been synthesized by reaction of substituted salicylaldehydes with ethyl 4‐chloro‐3‐oxobutanoate, in the presence of piperidine in CH₂Cl₂ at room temperature, in good yields.     

Synthesis and antimicrobial activity of 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides/sulfides

Novel 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides ( 4a–h ) were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenylmethane ( 2 ) with different aryl phosphorodichloridates ( 3a–g ) or bis(2‐chloroethyl)phosphoramidic dichloride ( 3h ) in the presence of triethylamine at 55–60°C, and the compounds 4i–l were prepared by reacting the 2,6,10‐trichloro‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfide ( 5 ) in situ with substituted phenols and thiophenol 5 was prepared by condensing 2 with thiophosphoryl chloride. IR, ¹H, ¹³C, ³¹P NMR, and mass spectra supported all the proposed structures. Several title compounds exhibited significant activity in the assays against the bacteria Bacillus subtilis and Escherichia coli and fungi Curvularia lunata and Aspergillus niger. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:10–15, 2001     

Synthesis ofN1‐3‐{(4‐Substituted aryl‐3‐chloro‐2‐oxo‐azetidine)‐iminocarbamyl}‐propyl‐6‐nitroindazole Derivatives and Their Biological Significance

Synthesis ofN¹‐3‐{(4‐substitute daryl‐3‐chloro‐2‐oxo‐azetidine)‐iminocarbamyl}‐propyl‐6‐nitroindazole 4a – 4s was conducted by a conventional method. All the compounds were synthesized and characterized by IR, ¹H NMR, ¹³C NMR, FAB‐Mass techniques and chemical methods. All the final synthesized compounds were evaluated for their antimicrobial activity and antitubercular activity with MIC values against some selected microorganisms.     

Reaktionen von 1,1,3,3‐Tetrakis(dimethylamino)‐1 λ5, 3 λ5‐diphosphet mit 5‐Cyano‐1‐pentin und mit 2‐(Cyanmethyl)‐1‐methylpyrrol

Diphosphabenzenes. VII. Reactions of 1,1,3,3‐Tetrakis(dimethylamino)‐1 λ⁵, 3 λ⁵‐diphosphete with 5‐Cyano‐1‐pentine and 2‐(Cyanomethyl)‐1‐methylpyrrol 5‐Cyano‐1‐pentine reacts with the equimolar amount of the λ⁵‐diphosphete 1 to give the λ⁵‐diphosphinine (λ⁵‐diphosphabenzene) ( 3 ), while reaction with the double equimolar amount of 1 yields the λ⁵‐diphosphinine ( 4 ). The acyclic compount 6 is the main product of the reaction between 1 and 2‐(cyanomethyl)‐1‐methylpyrrol, 5 . Melting points of 4 · CH₃CN and 6 , and mass, nmr and ir spectra of 3 , 4 , and 6 are reported. The crystal structure of 4 · CH₃CN shows an open‐chain ylidic CPCP‐sequence, which is linked to a λ⁵‐diphosphinine via an ethylene bridge. The X‐ray structure analysis of 6 confirms the existence as an acyclic conjugated double ylid.     

Mono‐ and Binuclear Rhodium and Platinum Complexes of 1, 3, 5‐Trimethyl‐1, 3, 5‐triaza‐2σ3λ3‐phosphorin‐4, 6‐dionyloxy‐substituted Calix[4]arenes

The reaction behaviour of 1, 3, 5‐triaza‐2σ³λ³‐phosphorin‐4, 6‐dionyloxy‐substituted calix[4]arenes towards mono‐ and binuclear rhodium and platinum complexes was investigated. Special attention was directed to structure and dynamic behaviour of the products in solution and in the solid state. Depending on the molar ratio of the reactands, the reaction of the tetrakis(triazaphosphorindionyloxy)‐substituted calix[4]arene ( 4 ) and its tert‐butyl‐derivative ( 1 ) with [(cod)RhCl]₂ yielded the mono‐ and disubstituted binuclear rhodium complexes 2 , 3 , and 5 . In all cases, a C₂‐symmetrical structure was proved in solution, apparently caused by a fast intramolecular exchange process between cone conformation and 1, 3‐alternating conformation. The X‐ray crystal structure determination of 5 confirmed [(calixarene)RhCl]₂‐coordination through two opposite phosphorus atoms with a P ⃜P separation of 345 pm. The complex displays crystallographic inversion symmetry, and the Rh₂Cl₂ core is thus exactly planar. Reaction of 1 and of the bis(triazaphosphorindionyloxy)‐bis(methoxy)‐substituted tert‐butyl‐calix‐[4]arene ( 7 ) with (cod)Rh(acac) in equimolar ratio and subsequent reaction with HBF₄ led to the expected cationic monorhodium complexes 5 and 8 , involving 1, 3‐alternating P‐Rh‐P‐coordination. The cone conformation in solution was proved by NMR spectroscopy and characteristic values of the ¹J(PRh) coupling constants in the ³¹P‐NMR‐spectra. Reaction of equimolar amounts of 4 with (cod)Rh(acac) or (nbd)Rh(acac) led, by substitution of the labile coordinated acetylacetonato and after addition of HBF₄, to the corresponding mononuclear cationic complexes 9 and 10 . Only two of the four phosphorus atoms in 9 and 10 are coordinated to the central metal atom. Displacement of either cycloocta‐1, 5‐diene or norbornadiene was not observed. For both compounds, the cone conformation was proved by NMR spectroscopy. Reaction of 4 with (cod)PtCl₂ led to the PtCl₂‐complex ( 11 ). As for all compounds mentioned above, only two phosphorus atoms of the ligand coordinate to platinum, while two phosphorus atoms remain uncoordinated (proved by δ³¹P and characteristic values of ¹J(PPt)). NMR‐spectroscopic evidence was found for the existence of the cone conformation in the cis‐configuration of 11 .     

5‐Chloro‐3‐methylthio‐1,2,4‐thiadiazol‐2‐ium chlorides as useful synthetic precursors to a variety of 6aλ4‐thiapentalene systems

Title salts 3 were easily obtained by treatment of formimidoyl isothiocyanates 1 with a twofold excess of methanesulfenyl chloride. They showed interesting chemical behavior toward several nitrogen and carbon nucleophiles. Substitution reactions with isothioureas and acetamide in the presence of triethylamine gave the 1H, 6H‐6aλ⁴‐thia‐1,3,4,6‐tetraazapentalenes 7 and 6H‐6aλ⁴‐thia‐1‐oxa‐3,4,6‐triazapentalene 9 , respectively. Addition of p‐toluidine furnished the 5‐imino‐thiadiazole derivatives 10 , which reacted further with diverse heterocumulenes to yield the corresponding thiatriaza‐ and tetraazapentalene species 11 . The N,N′‐bis(1,2,4‐thiadiazol‐5‐ylidene)diaminobenzenes 13 were also prepared and reacted with phenyl isothiocyanate. Two stable rotational isomers were separated for the 1,2‐phenylene product 14b . Other π‐hypervalent sulfur compounds 16 were synthesized under similar conditions from salts 3 and methyl cyanoacetate or dimethyl malonate. The structural assignments were discussed on the basis of IR and NMR spectroscopic data and received additional support from X‐ray analysis of substrate 16a . © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:95–105, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10106     

Phosphorus Centers of Different Hybridization in Phosphaalkene‐Substituted Phospholes

Phosphole‐substituted phosphaalkenes (PPAs) of the general formula Mes*P?C(CH₃)?(C₄H₂P(Ph))?R 5 a – c (Mes*=2,4,6‐tBu₃Ph; R=2‐pyridyl ( a ), 2‐thienyl ( b ), phenyl ( c )) have been prepared from octa‐1,7‐diyne‐substituted phosphaalkenes by utilizing the Fagan–Nugent route. The presence of two differently hybridized phosphorus centers (σ²,λ³ and σ³,λ³) in 5 offers the possibility to selectively tune the HOMO–LUMO gap of the compounds by utilizing the different reactivity of the two phosphorus heteroatoms. Oxidation of 5 a – c by sulfur proceeds exclusively at the σ³,λ³‐phosphorus atom, thus giving rise to the corresponding thioxophospholes 6 a – c . Similarly, 5 a is selectively coordinated by AuCl at the σ³,λ³‐phosphorus atom. Subsequent second AuCl coordination at the σ²,λ³‐phosphorus heteroatom results in a dimetallic species that is characterized by a gold–gold interaction that provokes a change in π conjugation. Spectroscopic, electrochemical, and theoretical investigations show that the phosphaalkene and the phosphole both have a sizable impact on the electronic properties of the compounds. The presence of the phosphaalkene unit induces a decrease of the HOMO–LUMO gap relative to reference phosphole‐containing π systems that lack a P?C substituent.     

Protonierung des 1,1,3,3,5,5‐Hexakis(dimethylamino)λ5‐[1,3,5]triphosphinins. Cyclotrimethylentriphosphinsäure. NMR‐Daten,Kristallstrukturen und quantenchemische Rechnungen

Protonation of 1,1,3,3,5,5‐Hexakis(dimethylamino)‐λ⁵‐[1,3,5]triphosphinine. Cyclotrimethylenetriphosphinic Acid. NMR Data, Crystal Structures, and Quantum Chemical Calculations Preparation of 1,1,3,3,5,5‐hexakis(dimethylamino)‐1,2‐dihydro‐3λ⁵,5λ⁵‐[1,3,5]triphosphininium‐tetrafluoroborate ( 3 ) und 1,1,3,3,5,5‐hexakis(dimethylamino)‐λ⁵‐[1,3,5]triphosphinanetriium‐tris(tetrafluoroborate) ( 4 ) from 1,1,3,3,5,5‐hexakis(dimethylamino)‐1λ⁵,3λ⁵,5λ⁵‐triphosphinine 1 and HBF₄ · O(C₂H₅)₂ are described. The structures of 3 und 4 are elucidated by n. m. r. and X‐ray structural analyses. By hydrolysis of 4 with conc. hydrochloric acid 1,3,5‐trioxo‐1λ⁵,3λ⁵,5λ⁵‐[1,3,5]triphosphinane‐1,3,5‐triol (cyclotrimethylene‐triphosphinic acid) ( 8 ) is formed. Neutralisation with NaOH yields its sodium salt 9 . 8 and 9 are characterized by their n. m. r. spectra. Quantum chemical calculations have been investigated for the compounds 1 ′– 4 ′ and the trianion 9 . The systems 1 ′– 4 ′ are distinguished from 1 – 4 by the size of the ligands at phosphorus which is reduced from N(CH₃)₂ to NH₂, respectively. The aims of the calculations are to elucidate hybridisations and molecular structures, Lewis or resonance structures, electronic charge distributions and NMR chemical shifts.     

Pyridinium Ylide Assisted Highly Stereoselective One‐Pot Synthesis of trans‐2‐(4‐Chlorobenzoyl)‐3‐aryl‐spiro[cyclopropane‐1,2′‐inden]‐1′,3′‐diones and Their Antimicrobial and Nematicidal Activities

A series of highly stereoselective polysubstituted cyclopropane derivatives were synthesized via one‐pot two‐step tandem reaction starting from pyridine, 4‐chloro phenacyl bromide, 1,3‐indandione and aromatic aldehydes in acetonitrile using triethylamine as catalyst. Pyridinium ylide generated from 4‐chloro phenacyl bromide undergo cyclopropanation with 2‐arylidene‐2H‐indene‐1,3‐dione in situ afford the title compounds. Structures of all the compounds were confirmed by their analytical and spectral studies. Single crystal X‐ray analysis was also performed on compound 4c in order to determine the crystal structure. All the compounds were screened for antimicrobial and nematicidal activities. Significant antimicrobial activity was shown by the compounds derived from 2‐hydroxybenzaldehyde ( 4i ) and 4‐(dimethylamino)benzaldehyde ( 4m ) against all the tested bacterial and fungal strains. Compound 4i has shown good activity (48% mortality) against Meloidogyne incognita after 48 h of exposure at 250 µg/mL concentration.     

Synthesis and spectral determination of new derivatives of 1‐[(p‐substituted)phenyl]‐3a‐[(o‐ and p‐substituted)phenyl]‐5‐chloro‐9‐methylthio‐10,3a‐dihydro‐[1,2,4]‐oxadiazolo[2,3‐b][1,4]benzodiazepines

A new synthesis to obtain eight novel derivatives of 1‐[(p‐substituted)phenyl]‐3a‐[(o‐ and p‐substituted)‐phenyl]‐5‐chloro‐9‐methylthio‐10,3a‐dihydro‐[1,2,4]‐oxadiazolo[2,3‐b][1,4]benzodiazepines with possible biological and pharmacological activity as anxiolytics, hypnotics, anticonvulsants in the central nervous system. The final products were obtained by condensation between 2‐methylthio‐5‐[(o‐; p‐substituted)‐phenyl]‐3H‐7‐chloro‐[1,4]benzodiazepine with benzonitrile oxide generated in situ from benzohydroxamoyl chloride in triethylamine. The structure of all products was corroborated by ir, ¹H‐nmr, ¹³C‐nmr, with experiments bidimensional and ms in low and high resolution.     

(σ3,λ5)‐phosphoranes versus (σ3,λ3)‐thiaphosphiranes: Quantum chemical investigation of products of phosphaalkene sulfurization

By sulfurization of phosphaalkenes ( a ) either (σ³,λ⁵)‐phosphoranes ( b ) or (σ³,λ³)‐thiaphosphiranes ( c ) are formed. In this study, Density Functional Theory (DFT) and coupled cluster (CCSD(T)) calculations have been carried out for model and experimental structures of (σ³,λ⁵)‐phosphoranes and (σ³,λ³)‐thiaphosphiranes to elucidate the factors influencing relative stabilities of b and c . According to the results of quantum chemical calculations, sterically bulky substituents make the phosphorane form more favored. Conversely, electronic effects of the most substituents provide higher stability for thiaphosphirane isomers. The only exception has been found in the cases where the substituent at the phosphorus atom possesses π‐donor and σ‐acceptor properties (e.g., in the case of amino group) and the substituents at carbon atom exhibit σ‐donor/π‐acceptor effects (e.g., silyl groups). The stability of the cyclic form c decreases further, if the substituents at the carbon atom are amino groups. In this case, a quite unusual structure has been theoretically predicted, which is considerably different from those of the hitherto known phosphoranes. It indicates a pyramidal configuration at the phosphorus atom and can be conventionally presented as a donor–acceptor adduct of diaminocarbene with thioxophosphine. © 2012 Wiley Periodicals, Inc.     

Palladium(II)‐Komplexe des 1,1,3,3,5,5‐Hexakis(dimethylamino)‐λ5‐[1,3,5]triphosphinins

Palladium(II) Complexes of 1,1,3,3,5,5‐Hexakis(dimethylamino)‐λ⁵‐[1,3,5]triphosphinine 1,1,3,3,5,5‐Hexakis(dimethylamino)‐1λ⁵‐3λ⁵‐5λ⁵‐[1,3,5]triphosphinine ( 5 ) reacts with (benzonitrile)₂PdCl₂ to give the chelate complex dichloro(dodeca‐N‐methyl‐1λ⁵,3λ⁵,5λ⁵‐1,3,5‐triphosphinine‐1,1,3,3,5,5‐hexaamin‐C²,C⁴)palladium ( 6 ). In a pyridine‐d₅ solution of 6 the complex dichloro(dodeca‐N‐methyl‐1λ⁵,3λ⁵,5λ⁵‐1,3,5‐triphosphinine‐1,1,3,3,5,5‐hexaamin‐C²)((²H₅)pyridine‐N)palladium ( 7 ) is formed. The solute 7 could not be isolated as a solid, because elimination of the solvent regenerates 6 quantitatively. Properties, nmr and ir spectra of 6 and 7 are reported. 6 is characterized by the results of an X‐ray structural analysis.