Abstract Phosphinoformic acid is unstable like the N-analogue carbamic acid. We found however that the acid can be stabilized by coordination via P to a (CO)5Cr-moiety [1]. In accordance with the conclusions of Leiserowitz [2] about solid carboxylic acids the crystal formic acid consists of hydrogen of the Cr atom is a distorted bonds between 1.881 and 1.928 A bond of 2.335 A. The angular distortion is small as shown by a maximum deviation of about 2.3° fiom the ideal geometry. At the P atom all bonding angles involving the Cr atom are widened to a maximum of 124° and the other ones are reduced to a minimum of 95°. In the crystal structure two symmetry-related molecules are connected to each other by means of two equivalent hydrogen bonds 06… 07′ and 07… 06′ of 2.660 c length between the carboxylic groups. Because of a twofold disorder along the bond P-C6, proven by bond lengths of 1.269(2) A for C6–06 and 1.264(2) A for C6–07 as well as by the localization and refinement of two H atoms with an occupancy ...

By reaction of RP(O)Cl-2 with RP(O)(OSiMe3)(2), phosphonic anhydrides (RPO2)(3) (R = tBu, 2-methylphenyl, 2,4,6-trimethylphenyl) Za-e are conveniently obtained. In contrast to 1b and 1c, compound 1a is remarkably stable against protolysis. Intermediates of hydrolysis of 1a, namely tris(tert-butyl)triphosphonic acid (2) and bis(tert-butyl)diphosphonic acid (3), can also be isolated in good yield. The structures of 1-3 were determined mainly by NMR spectroscopy (H-1, C-13, P-31). Assuming an energetic preference for the chair conformations in solution, and considering the steric requirements of the bulky substituents R, configurations Ia (point group C-s, two R in equatorial positions) for 1a and b, and IIa (point group C-3v, all R equatorial) for 1c are suggested. - Reaction of 1a with N-benzyloxycarbonylglycine (4) in methanol affords strong evidence that in the first step of peptide synthesis with (RPO2)(3), a mixed anhydride of triphosphonic acid and the N-protected amino acid is formed. - The crystal structure of 1a (monoclinic, space group P2(1)/n) widely corresponds to the suggested configuration Ia, but reveals an envelope conformation for the six-membered ring with a P3O2 plane in the crystal. In the crystal structure of the octahydrate of the disodium salt of 2 (monoclinic, space group P2(1)/c), it can be seen that the polar end groups of the anions [tBu(3)P(3)O(7)](2-) together with the water molecules and the Na+ cations form hydrogen-bonded double-layers, strictly separated from each other by the non-polar tert-butyl groups of the anions.

Molecules that behave like large atoms!—molecules of the mixed anhydride formed from the acids tBuP(O)(OH)2 and PhB(OH)2 exhibit this characteristic since in the crystal lattice they occupy the corners and centers of weakly distorted cubooctahedra. The molecules reveal a cubane framework (depicted on the right), whose corners are occupied alternately by phosphorus and boron atoms and whose edges are bridged by oxygen atoms.

Phosphonic acid anhydrides are useful condensation reagents in the peptide and polyamide synthesis [1,2]. A new method for the preparation of well defined anhydrides is now described and intermediates of the peptide synthesis are elucidated. Cryoscopic and mass spectrometric data confirm the suggested cyclic trimeric molecular structure and the 31P{1H}- as well as 1H-NMR spectra can be explained with the structures: Reaction of t-BuP(O)(SiMe3)2 and PhBCl2 yields the mixed anhydride of t-butylphos-phonic and phenylboronic acid C40H57B4O12P4. The compound forms colourless crystals and the obtained data are in agreement with a 16 membered P-0-B- ring.

Metal carbonyl complexes containing phosphinoformic acids, including the parent compound H2PCOOH, have been made by the following route: (CO)5MPRR'H-->(CO)5MPRR'Li-->(CO)5MPRR'COOLi-->(CO)5MPRR'COOSiMe3-->(CO)5MPRR'COOH (R = organyl, H; M = Cr, W).While the uncoordinated silyl esters RR'PCOOSiMe3 spontaneously decompose to RR'PH, CO2 and Me3SiOH in protic media the last step in the sequence above can be safely brought about by silica gel. So far only chromatography on silica gel has been found to provide the mild conditions necessary to avoid decarboxylation of the ligated esters during protolysis. Some reactions of (CO)5MPRR'COOLi are reported and compared with those of the free ligands RR'PCOOLi. The structures of the complexes have been confirmed by spectroscopic methods (IR, MS, H-1-, P-31-, C-13-NMR).

The preparation of lithiumphosphinoformates R(2)PCOOLi 1 (R = Ph, c-Hexyl, i-Pr, Et) and RHPCOOLi 2 (R = Ph, c-Hexyl) from R(2)PLi or RPHLi and CO2 is described. In the latter reaction RP(COOLi)(2) 3 and RPH(2) are formed in addition to 2. In protic media 1-3 are rapidly decomposed with decarboxylation and formation of R(2)PH and RPH(2), respectively. Reactions of 1 with Mel, (MeO)(2)SO2, Me(3)SiCl and CS2 are similar to those of Ph(2)PCOONa and no significant influence of R was detected. With (MeO)(2)SO2 mixtures of 2 and 3 gave esters RHPCOOMe and RP(COOMe)(2) while with Me(3)SiCl RHPCOOSiMe(3) was obtained as the sole product. Ab initio MO calculations (GAUSSIAN 90 system of programs; HF/3-21G*, HF/6-31G** and MP2/6-31G** basis sets) showed the phosphinoformic acid to be less stable than its decomposition products, from which it is separated by a high barrier of isomerization. Therefore the acid should be stable in the rarefied gas phase.

Removal of HCl from (CO)5MPRHCl (M  Cr, Mo, W; R  Ph, NEt2) by treatment with NEt3 has given the complexes (CO)5,MPh(H)PP(Cl)PhM(CO)5 (M Cr, Mo, W) (1) and (CO)5CrNEt2(H)PP(Cl)NEt2Cr(CO)5 (2) containing bridging diphosphine ligands. Surprisingly, (CO)5CrCl2PPCl2Cr(CO)5 (3) was formed from treatment of (CO)5CrPHCl2 with NEt3. Reaction of 1 with tetrabutylammoniumfluoride, of 2 with gaseous HCl, and of 3 with MeOH gave (CO)5,CrPh(H)PP(F)PhCr(CO)5, (4), (CO)5CrCl(H)PPCl2Cr(CO)5 (5) and (CO)5Cr(MeO)2PP(OMe)2Cr(CO)5 (6) respectively. Except for Cl2PPCl2, the diphosphine ligands in 1–6 are unknown in the free state. Attempts to abstract HCl from 1 to give the diphosphene complex (CO)5CrPhPPPhCr(CO)5 failed.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractStarting with Cr complexes of the type (I) new complexes of the type (II), (III), (IV), and (V) are obtained according to the scheme.

Starting from compounds (CO)5MPRClNEt2 (M = Cr, Mo, W) several new complexes have been obtained in which phosphines—non-existent or having a different tautomeric structure in the free state—are stabilized by coordination to a metal(0) centre. Thus, hydrolysis yields (CO)5CrPR(OH)2, methanolysis (CO)5CrPR(OMe)NEt2 and reduction with LiAlH4 (CO)5MPRHNEt2. The latter were converted into (CO)5MPRHCl with gaseous HCl.

Aminophosphine des Typs Rn 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—PRn (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)Rn (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 Rn 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—]2PRn (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)Rn (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”.

AbstractDepending on the molar ratio, the diamines (I) form with dithiodiphosphetanes, e.g. (II), monoinsertion products (III) or diinsertion products (IV).

ChemInformVolume 21, Issue 49 Organoelement Compounds ChemInform Abstract: Reactions of Sodium Diphenylphosphinoformate. K. DIEMERT, K. DIEMERT Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this authorT. HAHN, T. HAHN Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this authorW. KUCHEN, W. KUCHEN Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this author K. DIEMERT, K. DIEMERT Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this authorT. HAHN, T. HAHN Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this authorW. KUCHEN, W. KUCHEN Inst. Anorg. Chem. Strukturchem., Heinrich-Heine-Univ., D-40225 Duesseldorf, GermanySearch for more papers by this author First published: December 4, 1990 https://doi.org/10.1002/chin.199049220AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume21, Issue49December 4, 1990 RelatedInformation

Substitution of the carboxyl-group (-COOH) in substances of biological interest by the phosphinic acid group (-PH(O)OH) leads to “bioisosteric” compounds [1,2]. This concept is of great importance for the pharmaceutical and biochemical investigation as many of those biomimic compounds show remarkable biological activities.

Sodiumdiphenylphosphinoformiat 1, can easily be of Ph2PNa with CO2 [1]. Some reactions of 1 have reinvestigated by us.

Chiral phosphines L and L′ of general formula [(R2′N)ArP(S)-S-]nPR(NR2′)2-n(Ar=Aryl; L: n=1; L′: n=2)1–5 can behave as mono- or bidental ligands in metal(O)carbonyl complexes. With L compounds (CO)5ML(Ar: 4-Methoxyphenyl=An; R=Cyclohexyl, (-)Menthyl; R′=Me, Et; M=Cr, W) or chelate complexes (CO)4CrL (Ar: An; R=Ph, (-)Menthyl, t-Bu; R′=Me, Et) have been obtained. L being coordinated via γ′-P or γ′-P and S of the P(S)-group. In contrast to L the ligands L′ (Ar=An, 2-Naphthy1, 2-Thienyl; R=Ph, Cyclohexyl; R′=Me, Et) gives only chelates (CO)4CrL′ in which one of the two P(S)-groups of the ligand remains uncoordinated. Structures and stereoisomerism of these complexes are deduced from their IR- as well as their 31IP{1H}- and 13C-NMR-spectra. Die chiralen Phosphine L und L′ [(R2′N)ArP(S)-S-]nPR(NR2′)2-n (Ar=Aryl; L: n=1; L′: n=2)1–5 fungieren je nach den Reaktionsbedingungen in Metall(O)carbonylkomplexen als mono- oder bidentale Liganden. So erhält man mit L die Verbindungen (CO)5ML(Ar: 4-Methoxyphenyl=An; R=Cyclohexyl. (-)Menthyl; R′=Me, Et; M=Cr, W) oder Chelatkomplexe (CO)4CrL (Ar: An; R=Ph. (-)Menthyl, t-Bu; R′=Me. Et) durch Koordination von L über γ3-P oder γ3-P und S der P(S)-Gruppe. Mit L′ (Ar=An, 2-Naphthyl, 2-Thienyl; R=Ph. Cyclohexyl; R′=Me, Et) bilden sich dagegen nur Chelakomplexe (CO)4CrL′. in denen eine der beiden P(S)-Gruppen des Liganden nicht koordiniert wird. Struktur und Stereoisomerie der Komplexe werden aus IR- sowie 31P{1H)- und 13C-NMR-Spektren abgeleitet.