Thomas Kaukorat

N,N′,N′-trimethylethylenediamine as a substituent group at main group centers: intramolecular donor-acceptor interactions and unusual modes of coordination in compounds of silicon and phosphorus and their transition metal complexes

Abstract This review is concerned with the role of the N , N ′, N ′-trimethylethylenediamine group as a substituent at phosphorus atoms in different coordination and/or oxidation numbers. A few examples for silicon are also presented. Intramolecular donor-acceptor interactions between the nitrogen atom of the dimethylamino group and Si or P as the central atom were first noted in some N , N ′, N ′-trimethylethylenediamine-substituted fluorosilanes (LSiF 3 , PhSiF 2 L) and P(III)Cl systems, e.g. LPCl 2 and PhP(Cl)L (L = N , N ′, N ′-trimethylethylenediamine group). These observations gave rise to a more detailed study of the coordinating behavior, especially of further phosphorus compounds of different substitution pattern. Spontaneous intramolecular coordination with formation of salt-like products was observed, especially, for compounds in which a phosphorus-bonded halogen atom is available to dissociate as an anion. A dependence both on the nature of the halogen atom and on the nature of other ligands at P(III) [or P(V)] was noted and will be discussed. Through the action of Lewis acids, e.g. AlCl 3 of PF 5 , or in the reaction with tetraphenylborate as a non-coordinating anion, halide abstraction and consequent formation of the Me 2 N → P coordinative bond from cyclic N , N ′, N ′-trimethylethylenediamine-substituted halophosphines or trimethylethylenediamine-substituted fluorophosphoranes could be induced. No such Me 2 N → P coordination took place during oxidation of N , N ′, N ′-trimethylethylenediamine-substituted phosphorus(III) compounds with oxidizing agents, e.g. sulfur, selenium, o -quinones or hexafluoroacetone. Numerous oxidation reactions were conducted on intramolecularly stabilized phospholidin-1-ium salts. They furnished the expected oxidation/addition products. This was accompanied in some cases (depending on the nature of the substituents at P(III)) by a scission of the coordinative Me 2 N → P bond. The reaction of phospholidin-1-ium salts with phenyl azide, dimethyl sulfoxide and sulfur furnished phosphonic acid diamides and substituted λ 4 -phospholidin-1-ium salts, as well as substituted diazadiphosphetidines, as a result of the dimerization of PN species. Intramolecular donor-acceptor interaction in N , N ′, N ′-trimethylethylenediamine-substituted fluorophosphoranes was only observed in the presence of the Lewis acid, phosphorus pentafluoride leading to the formation of hexafluorophosphate salts. The reaction of dialkylamino-substituted tetrafluorophosphoranes with N , N ′, N ′-trimethylethylenediamine took an unusual course. Instead of the expected PF cleavage and formation of an N , N ′, N ′-trimethylethylenediamine-substituted dialkylaminotrifluorophosphorane, cyclic tetrafluorophosphates with a λ 6 P atom, and dialkylaminotrimethylsilane were formed. The reaction of phosphorus(III)- N , N ′, N ′-trimethylethylenediamine compounds with transition metal compounds [Fe(0), Cr(0), Mo(0), Pt(II)] furnished mono-, di- or trisubstituted coordination compounds, depending on the nature of the metal. The P(III) ligand was bonded in some cases via P(III) only (as a monodentate ligand) and in other cases as a chelating ligand coordinated via P(III) and N. A variety of variable-temperature NMR experiments have examined the dynamic processes occurring at room temperature in solution, and X-ray single-crystal structure determinations have been conducted in many cases to characterize these new and unusual compounds.

VERBINDUNGEN MIT DEM 1,3,2- BENZODIAZAPHOSPHORINAN-4-ON GRUNDGERÜST: SYNTHESE VON NEUARTIGEN N,N′,N′- TRIMETHYLETHYLENDIAMINSUBSTITUIERTEN DERIVATEN MIT DREI- UND VIERFACH KOORDINIERTEM PHOSPHOR

Abstract The reaction of N,N′-dimethylanthranilic amide with phosphorus trichloride furnished 3, the first compound of P(III), involving the 1,3,2-benzodiazaphosphorinanone ring system. In the reaction of 3 with N-trimethylsilyl-N,N′,N′-trimethylethylenediamine 2 the product 4 was formed. The possibility of in tramolecular donor-acceptor-interaction between the nitrogen atom of the (CH3)2N group and the λ3P atom was investigated by 1H n.m.r. studies. No interaction was observed. Oxidative addition of elemental sulfur at the λ3P atom of 4 gave the λ4P-thiophosphoryl compound 5 while the reaction of 4 with methyl iodide and bromine, in an unusual reaction, furnished the ammonium salts 6 and 7. The N-Br bond in 7 was established by IR-spectroscopy. In the reaction of 4 with C7H8Cr(C0)4 (C7H″ = norbornadiene) a substitution product 8, involving intramolecular coordination of 4 to Cr(O) via λ3P and the nitrogen atom of the (CH3)2N grouping was formed. By contrast, the reaction of C7118Mo(CO)3 (C7H8 = cyclohept...

BENZODIAZA-, BENZOXAZA-, AND BENZODIOXAPHOSPHORINONES - FORMATION, REACTIVITY, STRUCTURE, AND BIOLOGICAL ACTIVITY

Abstract Although diverse phosphorus-containing heterocycles had been synthe-sized during the late nineteenth century already, work was still sparse in this area as recently as 1950[1,2]. The realization, around 1950, of the importance of phosphorus-containing substances in biological processes resulted in intense activity in preparative organophosphorus chemistry, and in an upsurge of research on structural and mechanistic problems [3–6].

UMSETZUNGEN VON 4-CHLOR-1,3,5,7-TETRAMETHYL-1,3,5,7-TETRAAZA-4λ5- PHOSPHASPIRO[3,3]HEPTAN-2,6-DION, BIS(TRIMETHYLSILYL)- TRIMETHYLBIURET UND BIS(2-CHLORETHYL)- AMINOPHOSPHORSÄUREDICHLORID MIT Me2NCH2CH2N(Me)SiMe3; STUDIUM INTRAMOLEKULARER P-N-WECHSELWIRKUNGEN

Abstract A study of possible donor-acceptor interactions in N,N′,N′-trimethylethylenediamine-substituted phosphorus compounds has been conducted. Neither the trimethylethylenediamine-substituted λ5P-spirophosphorane 3 nor compound 6, a λ3P-trimethylethylenediamine-substituted derivative of trimethylbiuret, showed any evidence for intramolecular interaction (1H n.m.r. spectroscopy). In the case of the bis(2-chloroethyl)amino-substituted compounds 9 and 10 dynamic behaviour was observed by n.m.r. spectroscopy. By 31P n.m.r. spectroscopy three isomers (a-c) were established. The dimerization of isomer a with formation of two dioxaphosphetidine structures (b and c) is suggested to occur, as are cis and trans isomers, b and c. No reaction occurred between N,N′-dimethylanthranilic acid amide and bis(2-chloroethyl)aminophosphoric acid dichloride, in contrast to the analogous reaction with methylphosphonic acid dichloride. Electronic reasons are thought to be responsible for the lack of reactivity of bis(2-chloro...

The 4-chloro-2-oxo-1,3,5,5,8-pentamethyl-1,3,8-triaza-5-azonia-4λ5-phosphaspiro[3.4]octyl cation: X-ray crystal structure determination and variable temperature 1H NMR spectra

Abstract The 1H NMR spectrum of the spirophosphorane 1 at room temperature indicates dynamic behaviour of the cation. From high and low temperature 1H NMR spectra it is concluded that exchange between the N(CH3)2 groups and between the NCH3 groups in the four-membered ring takes place. The free enthalpy of activation for this dynamic process was determined (62.4±2.5 kJ mol−1). In the reaction of 1 with sodium tetraphenylborate the crystalline compound, 2, involving the non-coordinating anion, [B(C6H5)4]−, was obtained. The X-ray crystal structure analysis of 2 reveals the presence of a five-membered ring, formally as a result of intramolecular donor-acceptor interaction between the nitrogen atom of the N(CH3)2 group and phosphorus.

Reactions of 2H-2-oxo-phosphorinanone derivatives and dimethylphosphine oxide with perfluorinated mono- and di-ketones

Abstract 5,6-Benzo-1,3-dimethyl-2 H -2-oxo-1,3,2λ 4 -diazaphosphorinan-4-one (1) and 1,3,5-trimethyl-2 H -2-oxo-1,3,5-triaza-2λ 4 -phosphorinan-4,6-dione (2) were allowed to react with perfluoro-isobutylmethyl ketone (4), perfluoro-1-methyl-2-isopropyl diketone (5) and perfluoro-1-methyl-2-n-propyl diketone (6), leading to the products 7-12 by formation of a P-O-C bond and migration of the hydrogen atom from phosphorus to the carbonyl carbon atom as a result of an O-addition reaction. In the reaction of 2 with 6, the formation of two isomers 12a and 12b was observed. Reaction of a mixture of 12a and 12b with water led to 2-hydroxy-2-oxo-triazaphosphorinan-4,6-dione (15) and two further perfluorinated products 13 and 14. Dimethylphosphine oxide (3) reacted with perfluoro-isobutylmethyl ketone (4) to give the perfluoroalkyl-substituted α-hydroxyphosphine oxide 16. In contrast to 7-12, compound 16 was shown to contain the P-C-OH fragment rather than a P-O-C bond. The existence of 7-9 in diastereomeric pairs and of 16 as an enantiomeric pair has been established by 1 H, 13 C and 19 F NMR spectroscopy. All compounds were characterized by NMR spectroscopy, mass spectrometry and elemental analysis. X-Ray crystal structure analyses have been carried out for the substituted diaza- and triaza-phosphorinanones 9 and 11. Compound 9 crystallizes as two independent molecules, which are, however, closely similar. Hydrogen bonds of the form C-H····O are observed for 9 and (weakly) in 11; the fluorine substituents presumably make the chain H atoms more positive.

New hydrogenated and didehydrogenated 1,2-diamines of quincorine and quincoridine

Abstract Four new members of the family of 1,2-diamines of quincorine and quincoridine have been synthesized, being hydrogenated and didehydrogenated at the C10–C11 fragment. The alkynes, containing an additional amino group at C9, are potentially useful building blocks for cross-coupling reactions. Additional investigations concerning the chemical properties of the molecules point to a significant impact of the remote C5 substituent on the basicity of the bridgehead nitrogen.

FORMATION OF SULFINAMIDES AND SULFONAMIDES BEARING THE ORGANO-AMINOMETHYLENE-DIMETHYLPHOSPHINE OXIDE OR SULFIDE GROUP

Abstract The reaction of N-methyl-N-trimethylsilylaminomethylene-dimethylphosphine oxide 1 and sulfide 2 with various sulfinyl and sulfonyl chlorides furnished, in good yield, a series of phosphorus-containing sulfinamides and sulfonamides. All, bearing the dimethylphosphoryl and thiohosphoryl group, respectively. All sulfinamides (3–8) show a complicated splitting pattern for the 1H-n.m.r. resonances of the CH 2P-group, due to the presence of a chiral sulfur atom. For the same reason, doubling of the (CH 3)2P-proton resonances is observed for 3, 4, 7 and 8. N.m.r. spectra for the sulfonamides 9–11 are in accord with expectation. N-benzylaminomethylene-dimethylphosphine oxide 12 was allowed to react with chlorosulfonyl-acetic acid methyl ester in the presence of triethylamine as a base to form the phosphorus-containing sulfonamide 13 in good yield. In the reaction of 5 with air/moisture, by an unknown reaction course, the phosphorus-containing ammonium hydrogen sulfate 14 was formed. X-ray crystal structu...

Das 2-Halogen-5,6-benzo-1,3,2-dioxaphosphorinan-4-on-Ringsystem / The 2-Halogeno-5,6-benzo-1,3,2-dioxaphosphorinan-4-one Ring System

The reaction of salicylic acid with phosphorus trichloride furnished the previously known 2-chloro-5,6-benzo-1,3,2-dioxaphosphorinan-4-one heterocycle 1 which was unambiguously characterized, for the first time, by NMR spectroscopy and mass spectrometry. The fluorine and bromine analogues of 1, 2 and 3 were synthesized from 1, using exchange reactions. The iodo derivative, 4, owing to its instability, could be identified only in the reaction mixture by 1H and 31P NMR spectroscopy. The amine derivatives 5-8 were obtained from 1 using standard exchange reactions, either with silylated amines or with secondary amines in the presence of base. There was no evidence by 1H NMR spectroscopy for intramolecular Me2N→P coordination in 6. The 31P NMR investigation of 7 revealed the presence of two rotational isomers, presumably as a result of steric hindrance at the P–N bond by the methyl substituent of the piperidine group. The reaction of 6 with methyl iodide led to methylation at the nitrogen atom of the Me2N group, producing the ammonium iodide, 9. The reactions of 5,6 and 8 with norbornadiene tetracarbonyl molybdenum failed to furnish isolable products.

Über intramolekulare Donator-Akzeptor-Wechselwirkungen in N,N′-Dimethylharnstoff-Derivaten des Phosphors / Intramolecular Donor-Acceptor Interactions in N,N′-Dimethylurea Derivatives of Phosphorus

The reaction of 1 with N, N′-dimethyl-N, N′-bis(trimethyIsilyl)urea, 2 has furnished the compound Me2NCH2CH2N(Me)P(NMe)2C(:O), 3. Following oxidation o f phosphorus in 3 through several reagents, intramolecular donor-acceptor interactions were observed when an electronegative group was bonded to phosphorus; this group, activating the phosphorus atom, should be well polarizable in solution and should readily depart from the molecule as an anion. The unusual spirophosphoranes 8, 11 and 12 could thus be synthesized. The reaction of equimolar quantities of MeOCH2CH2OPCl2, 15 with 2 has furnished 16 which is related to 3. Reaction of 15 with excess 2 constitutes a new mode o f formation of the previously reported diphosphorus compound 17.