Ambident PCN Heterocycles: N- and P-Phosphanylation of Lithium 1,3-Benzazaphospholides

Synthetic and structural aspects of the phosphanylation of 1,3-benzazaphospholides 1(Li), ambident benzofused azaphosphacyclopentadienides, are presented. The unusual properties of phospholyl-1,3,2-diazaphospholes inspired us to study the coupling of 1(Li) with chlorodiazaphospholene 2, which led to the N-substituted product 3. Reaction of 1(Li) with chlorodiphenyl- and chlorodicyclohexylphosphane likewise gave N-phosphanylbenzazaphospholes 4 and 5, whereas with the more bulky di-tert-butyl- and di-1-adamantylchlorophosphanes, the diphosphanes 6 and 7 are obtained; in the case of 7 they are isolated as a dimeric LiCl(THF) adduct. Structural information was provided by single-crystal X-ray d…

Mercurated and Palladated Iminophosphoranes. Synthesis and Reactivity

Reaction of the iminophosphorane Ph3PNC6H4Me-4 (1a) with Hg(OAc)2 and LiCl gives the mercurated iminophosphorane [Hg{C6H3(NPPh3)-2-Me-5}Cl] (2). The latter reacts with NaBr to give [Hg{C6H3(NPPh3)-2-Me-5}Br] (3). 2 reacts with MeC6H4NCO-4 or CX2 (X = O, S) to give [Hg{C6H3(NCNC6H4Me-4‘)-2-Me-5}Cl] (4) or [Hg{C6H3{NCNC6H3(HgCl)-1‘-Me-5‘}-2-Me-5}Cl] (5), respectively. Iminophosphoranes Ph3PNC6H4R-4 (1b) react with Pd(OAc)2 to give the complexes [Pd{κ2-C,N-C6H4(PPh2NC6H4R-4‘)-2}(μ-OAc)]2 (R = Me (6a), MeO (6b)), in which the palladation takes place at one of the phenyl substituents of the PPh3 group. Complex 6b reacts with NaBr or tBuNC to give [Pd{κ2-C,N-C6H4(PPh2NC6H4OMe-4‘)-2}(μ-Br)]2 (7) o…

Ambident Reactivity of P˭CH‒N‒Heterocycles: Lithiation and Substitution Sites

Abstract Benzofused 1H-1,3-azaphospholes are lithiated at the N-atom by tBuLi but phosphinylation takes place at either the N- or the P-atom. Smaller chlorophosphines react at nitrogen, bulkier react at phosphorus. Substituents at C2 promote the latter mode. N-Substituted 2H-1,3-benzazaphospholes undergo CH-metalation or addition at the P˭C bond, depending on the conditions, and allow access to 2-functionally substituted benzazaphospholes or their 2,3-dihydro derivatives, new σ2P,X or σ3P,X hybrid ligands (X=O,P).

New Carbenegold(I) Complexes Synthesized by the “Acac Method”

The reaction of [AuCl{C(NEt2)NHtBu}] with Tl(acac)] (1:1) gives [Au(C-acac){C(NEt2)NHtBu}] (1). Complex 1 reacts with 2-pyridinethiol (HSpy-2), C6H4(C⋮CH)2−1,3 (2:1), [Ph3PCH2CO2Me]ClO4, [Me3S(O)]ClO4, or [Me3NH]ClO4 to give, respectively, [Au(Spy-2){C(NEt2)NHtBu}] (2), [{AuC(NEt2)NHtBu}2(μ−C⋮CC6H4C⋮C-3)] (3), [Au{C(NEt2)NHtBu}{CH(PPh3)CO2Me}]ClO4 (4), [Au{C(NEt2)NHtBu}{CH2S(O)Me2}]ClO4 (5), or [Au{C(NEt2)NHtBu}(NMe3)]ClO4 (6). The crystal structures of 1, 3, and 5 have been determined.

Synthesis and Reactivity toward Isonitriles of (2-Aminoaryl)palladium(II) Complexes

Mixtures of “Pd(dba)2” (dba = dibenzylideneacetone) and 2,2‘-bipyridine (bpy; 1:2) or N,N,N‘,N‘-tetramethylethylenediamine (tmeda; 1:1) react with 2-bromo-4-nitroaniline to give [Pd{C6H3NH2-2-NO2-5}Br(N−N)] (N−N = bpy (1b), tmeda (1b‘)). Reactions of 2-iodoaniline with mixtures of “Pd(dba)2” and isonitriles RNC (R = C6H3Me2-2,6 (Xy), 2:1:2 molar ratios; R = tBu, 2.9:1:2 molar ratios) result in the formation of the complexes [Pd{κ2C,N-C(NXy)C6H4NH2-2}I(CNXy)] (2a) and trans-[Pd{C(NtBu)C6H4NH2-2}I(CNtBu)2] (3a*). The reactions of [Pd{C6H4NH2-2}I(bpy)] and 1b‘ with RNC give the complexes trans-[Pd{C(NR)C6H3NH2-2-Y-5}}X(CNR)2] (Y = H, X = I, R = Xy (3a), tBu (3a*); Y = NO2, X = Br, R = Xy (3b),…

The Reaction of 4-Amino-2-oxazolines with Isocyanates and Isothiocyanates. Synthesis and X-Ray Structures of Polysubstituted 2-Imidazolidinones, 1,3-Oxazolidines and 1,3-Thiazolidines.

Abstract Reactions of 4-alkylamino-2-phenyl-2-oxazolines 1 with isocyanates and isothiocyanates provide unprecedented efficient and regioselective heterocycle–heterocycle transformations. Compounds 1 reacted rapidly with tosyl isocyanate yielding directly 3-alkyl-4-benzamido-1-tosyl-2-imidazolidinones 4 in almost quantitative yields. The corresponding ureido intermediates 2 were not isolable species. However, the reactions with non-sulfonylated isocyanates or isothiocyanates were slower, leading to the expected ureido and thioureido derivatives 5, which were easily and efficiently transformed to either polysubstituted 2-imino-1,3-oxazolidine or 2-imino-1,3-thiazolidine hydrochlorides 7, res…

40(th) EASD Annual Meeting of the European Association for the Study of Diabetes : Munich, Germany, 5-9 September 2004

Synthesis and Reactivity of Ortho-Mercuriated and Ortho-Palladated Arylacetals and Cyclic and Acyclic Aryldithioacetals. New Examples of the Rearrangement of Acyclic Dithioacetal Aryl- to Dithioether Alkyl-Palladium Complexes

The arylmercurial [Hg{C6H3(CHO)2-2,5}Cl] (1) reacts with CH(OMe)3 or HS(CH2)2SH to give [Hg{C6H3{CH(OMe)2}2-2,5}Cl] (2) or [Hg(Ara)Cl] [Ara = C6H3{CH(SCH2CH2S)}2-2,5 (3a)], respectively. The mercur...

Electrochemical synthesis of 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles and (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP computational study of the topomerization mechanism of aryliminodioxoles

Abstract Cathodic reductions of 2,2′-furils in the presence of N-arylcarbonimidoyl dichlorides lead to 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles in high yields, along with minor amounts of (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP density functional theory methods have been applied to the determination of molecular geometries and to study the topomerization mechanism of aryliminodioxoles. The molecular structure of (E)-1,2-di(2-furyl)vinylene bis[N-(2-chloro-4-methylphenyl)chloroformimidate] has been determined by X-ray crystallography and compared with the calculated structure.

ChemInform Abstract: Electrochemical Synthesis of 2-Arylimino-4,5-di(2-furyl)-1,3-dioxoles and (E)-1,2-Di(2-furyl)vinylene Bis(N-arylchloroformimidates). HF and B3LYP Computational Study of the Topomerization Mechanism of Aryliminodioxoles.

Abstract Cathodic reductions of 2,2′-furils in the presence of N-arylcarbonimidoyl dichlorides lead to 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles in high yields, along with minor amounts of (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP density functional theory methods have been applied to the determination of molecular geometries and to study the topomerization mechanism of aryliminodioxoles. The molecular structure of (E)-1,2-di(2-furyl)vinylene bis[N-(2-chloro-4-methylphenyl)chloroformimidate] has been determined by X-ray crystallography and compared with the calculated structure.

Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations

European Community Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G x E), however, so far, thorough replication of findings is rare and G x E research still faces several conceptual and methodological challenges. in this article, we aim to review these recent developments and illustrate h…

Insertion of One, Two, and Three Molecules of Alkyne into the Pd−C Bond of Ortho-palladated Primary and Secondary Arylalkylamines

The ortho-metalated complex [Pd2{κ2(C,N)-C6H4CH2CH2NHMe-2}2(μ-Br)2] (1) can be prepared by refluxing a 1:1 mixture of Pd(OAc)2 and N-methylphenethylamine in acetonitrile, followed by addition of an excess of NaBr. Complex 1 reacts with PPh3 to give the mononuclear derivative [Pd{κ2(C,N)-C6H4CH2CH2NHMe-2}Br(PPh3)] (2). The cationic complex [Pd{κ2(C,N)-C6H4CH2CH2NHMe-2}(py)2]ClO4 (3) can be obtained by reacting 1 with AgClO4 and pyridine. The previously reported complex [Pd2{κ2(C,N)-C6H4CH2NHCH2Ph-2}2(μ-Br)2] (A) reacts with PhC≡CCO2R (R = Me, Et) to give the monoinserted derivatives [Pd2{κ2(C,N)-C(Ph)═C(CO2R)C6H4CH2NHCH2Ph-2}2(μ-Br)2] (R = Me (4a), Et (4b)). These dimers react with neutral l…

Metal NHC Complexes with Naphthalimide Ligands as DNA-Interacting Antiproliferative Agents

Naphthalimide-based N-heterocyclic carbene (NHC) complexes of the type [(1,5-cyclooctadiene)(NHC)RhCl)] (4 a-c), [(p-cymene)(NHC)RuCl2 )] (5 a-c), and [(NHC)CuBr] (6 a-c) were synthesized and investigated as antiproliferative agents that target DNA. The cytotoxic effects were largely driven by the naphthalimide structure, which is a DNA-intercalating moiety. Regarding the metal center, the highest activities were observed with the rhodium complexes, and cytotoxic activity was significantly lower for the ruthenium derivatives. The stable coordination of the NHC ligands of selected complexes 4 b and 5 b in solution was confirmed, and their DNA binding properties were studied by UV/Vis spectro…

CCDC 1510249: Experimental Crystal Structure Determination

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