Bridgehead diphosphines in the bicyclo[3.3.3]undecane and bicyclo[4.4.4]tetradecane series: synthesis, structure and properties

Several propellane diphosphonium salts 8 are prepared by the reaction of 1,k + 2-diphosphabicyclo[k.l.0]alkanes 6 with α,ω-alkanediol bis-triflates [bis(trifluoromethanesulfonates)]; their properties are strongly dependent on ring size. 1,6-Diphosphoniatricyclo[4.4.4.0]tetradecane bis-triflate 8d is stable in acidic aqueous solution, and reacts with nucleophiles [X = F–, MeO–, H– (from BH4–) and R– (from Grignard and alkyllithium reagents)] to give products 13–18 with partial X–P–P+ bonding, hydroxide ion gives the diphosphine monooxide 12b but even this may retain some P–P bonding. However 1,5-diphosphoniatricyclo[3.3.3.0]undecane bis-triflate 8a is hydrolysed irreversibly and much more rapidly than its [4.4.4.0] counterpart. 1,6-Diphosphoniatricyclo[4.4.3.0]tridecane bis-triflate 8c reacts with NaBH4 to give a hydride adduct 15a which is deprotonated by BunLi to give 1,6-diphosphabicyclo[4.4.3]tridecane 9c. However several attempts to prepare 1,6-diphosphabicyclo[4.4.4]tetradecane 9d led to a deep-seated rearrangement to give 1,4-bis(1-phospholan-1-yl)butane. These included reaction of hydride adduct 15b with BunLi, and debenzylations of 1-benzyl-1-phosphonia-6-phosphabicyclo[4.4.4]tetradecane trifluoromethanesulfonate 16b and 1,6-dibenzyl-1,6-diphosphoniabicyclo[4.4.4]tetradecane bromide triflate 21 with LiAlH4. Reaction of cis-1,5-dibenzyl-1,5-diphosphacyclooctane with CH2(CH2OTf)2 gives 1,5-dibenzyl-1,5-diphosphoniabicyclo[3.3.3]undecane bis-triflate which is debenzylated with LiAlH4 to 1,5-diphosphabicyclo[3.3.3]undecane 9a. Attempts to prepare 1,6-diphosphabicyclo[4.4.4]tetradecane by related methods lead to oligomerisation reactions. The structure of 1,5-diphosphabicyclo[3.3.3]undecane is reported; its He(I) photoelectron spectrum shows two well separated bands at 7.58 and 8.14 eV, and RHF/6-31G* ab initio calculations indicating that this is due to through-bond interactions.

[1]  R. Alder,et al.  In/Out Isomerism. , 1996, Chemical reviews.

[2]  J. Verkade.  Main group atranes: chemical and structural features , 1994 .

[3]  J. Verkade.  Atranes: New Examples with Unexpected Properties , 1993 .

[4]  G. Krippner,et al.  Concerning attempts to synthesize out-bicyclo[4.4.4]tetradec-1-ene derivatives , 1992 .

[5]  M. Gingras.  Tetrabutylammonium difluorotripheylstannate as a new anhydrous synthetic equivalent to TBAF , 1991 .

[6]  A. Zschunke,et al.  1,5‐Diphosphabicyclo[3.3.1]nonan , 1991 .

[7]  R. Alder.  Strain effects on amine basicities , 1989 .

[8]  D. V. Aken,et al.  Phosphatranes as unusual stabilizing structures for hypervalent phosphorus: 10-P-5 mono- and divalent cations , 1986 .

[9]  J. Verkade,et al.  New hypervalent phosphorus compounds: neutral and cationic 10-P-5 species from O:P(OCH2CH2)3N and Lewis acids , 1985 .

[10]  D. Schomburg,et al.  Preparation and Structure of a Diphosphorus Compound with Positive Charges on the Two Directly Bonded Phosphorus Atoms , 1985 .

[11]  F. Weinhold,et al.  Natural population analysis , 1985 .

[12]  R. Sessions,et al.  PROTON AFFINITIES AND IONIZATION ENERGIES OF BICYCLIC AMINES AND DIAMINES - THE EFFECTS OF RING STRAIN AND OF 3-ELECTRON SIGMA-BONDING , 1981 .

[13]  E. Lindner,et al.  Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, XI1) Darstellung und Eigenschaften von Ethandiyl‐, Propandiyl‐, Pentandiyl‐ und Decandiyl‐bis(trifluormethansulfonat) , 1981 .

[14]  A. Imamura,et al.  An analysis of the through-bond interaction using the localized molecular orbitals with ab initio calculations—I : Lone-pair orbital interactions in cis- and trans-hydrazines , 1981 .

[15]  R. Sessions,et al.  1,6-Diazabicyclo[4.4.4]tetradecane and its oxidized ions , 1979 .

[16]  R. Sessions,et al.  INSIDE-PROTONATED AND OUTSIDE-PROTONATED IONS FROM 1,6-DIAZABICYCLO[4.4.4]TETRADECANE , 1979 .

[17]  E. Heilbronner,et al.  A Quantitative Assessment of „Through‐space”︁ and „Through‐bond”︁ Interactions. Application to Semi‐empirical SCF Models , 1975 .

[18]  V. Grakauskas,et al.  Synthesis of some novel trifluoromethanesulfonates and their reactions with alcohols , 1973 .

[19]  L. Horner,et al.  Phosphororganische Verbindungen, XXXVII. Versuche zum Vorgang der Wasserstoffübertragung, VII. Reduktionspotentiale einiger quartärer Phosphonium‐ und Arsoniumsalze , 1963 .

[20]  S. A. Buckler,et al.  Phosphorus Compounds. II. Synthesis of Unsymmetrical Tertiary Phosphines1,2 , 1960 .

[21]  L. Horner,et al.  Phosphororganische Verbindungen, XIX. Reduktion von Phosphorverbindungen mit Alkalimetallen , 1959 .

[22]  S. A. Buckler,et al.  Phosphorus Compounds. I. Reduction of Benzylphosphonium Compounds with Lithium Aluminum Hydride1 , 1957 .