Patent GB-1301694-A (GB)
IPC: C07F5/00
Filed: 1970-02-19
Abstract: 1301694 Organic Lewis base-inorganic lithium salt complexes ESSO RESEARCH & ENG CO 19 Feb 1970 [18 March 1969] 7959/70 Headings C2B and C2C [Also in Divisions C1 C3 C5 and C7] Novel complexes comprising (a) an inorganic Li salt having a lattice energy of not more than that of lithium hydride and (b) a monomeric or polymeric polyfunctional Lewis base containing at least one functional group selected from secondary or tertiary amine, amine oxide, secondary or tertiary phosphine, phosphine oxide, thioether, sulphone and sulphoxide and at least one other functional group selected from the above groups or an ether group, are prepared by mixing the two components, optionally in the presence of an organic diluent, or by anion or Lewis base exchange in a preformed complex. At least the minimum stoichiometric amount of Lewis base is used in forming the complex, although for a given Li salt/Lewis base pair, more than one type of complex may be formed. Many Li salts are specified in which the preferred anions are Cl, Br, I, AlH 4 , BH 4 , NO 2 , BF 4 , hexafluorophosphate, tetraphenylborate, Al(C 2 H 5 )H 3 , Al(C 2 H 5 ) 2 H 2 , Al (C 2 H 5 ) 3 H, Al(C 2 H 5 ) 4 , ClO 4 , AsF 6 , BeF 4  and azide. The Lewis base may be non-chelating or, chelating in nature, the latter being preferred as it gives more stable complexes. Specified Lewis bases include polyalkylene polyamines, including heterocyclic polyamines, aminoethers, and polyamine oxides. Chelating bases include sparteine, bispidins and compounds of the formula in which a is 1 or 2, b is 0 or 1, c is 0 or 1-10,000, d is 0, 1 or 2, e is 0 or 1-3, R is C 1-4  alkyl, R<SP>1</SP> is hydrogen when d is 0 or C 1-4  alkyl, or C 6-10  aryl or aralkyl when d is 0, 1 or 2, Y is N, S or P, Y<SP>1</SP> is 0, N, S or P, Z is selected from (1) C 4-10  cycloaliphatic or aromatic radicals, or C 1-6  alkyl derivatives thereof, attached to Y and Y<SP>1</SP> in Formula I or N-atoms in Formula II at 1,2- positions on aromatic rings or 1,2- or 1,3- positions on cycloaliphatic rings, and (2) C 1-4  polymethylene radicals in which each carbon is optionally substituted by up to 2 C 1-6  hydrocarbon groups. The complexes are usually solids and can be decomposed to their components by addition of polar solvents, aqueous or anhydrous acids or bases or, preferably, by heating to, e.g. 30-250‹C. The variable stabilities and hydrocarbon-solubilities of the complexes can be used to separate mixtures thereof and provide a technique for purification and separation of mixtures of Lewis bases, including separation of cis and trans isomers, e.g. on a column using counter flow methods. The complexes in which the anion is derived from a metal hydride are useful reducing agents, particularly for the reduction of carbonyl groups. The complexes can absorb some compounds, particularly gases, and the resulting product used to introduce the absorbed compound into a reaction mixture, e.g. absorbed halogen for halogenation of double bonds. Aromatic compounds, including the Lewis bases containing aromatic rings, react with the complexes to form lithio anion complexes. Examples 1-19, 22 and 23 relate to the preparation of complexes of the Li salts specified above and tetramethyl-1,2-ethanediamine, tetramethyl - 1,2 - cyclohexanediamine, pentamethyl - diethylene - triamine, hexamethyltriethylenetetramine, hexamethyl - 1,3,5- cyclohexanetriamine, N,N<SP>1</SP>,N<SP>11</SP>-trimethylhexahydro-5-triazine, tetramethyl-o-phenylenediamine, 2-(dimethylamino)ethyl methyl ether, 1,2 - bis - (piperidino) - ethane, tetramethyl- 1,6 - hexanediamine, tetramethyl - 1,4-butanediamine, N<SP>1</SP> - phenyl - N,N,N<SP>11</SP>,N<SP>11</SP> - tetramethyl - diethylenetriamine, tetramethyl- 1,2 - cyclo-octanediamine and tetramethylmethanediamine. In Example 17, cis and transtetramethyl - 1,2 - cyclo - ootanediamine, obtained by CHO/HCOOH methylation of the diamine, are separated and purified by VPC of the LiBr complex. In Example 21 diethyl hexahydrophthate is reduced to trans-1,2-cyclohexanedimethanol with LiAlH 4 -pentamethyl-diethylenetriamine complex. Other specified uses of the complexes include separation of Li salts, modification and preparation of addition polymers, electrochemical application and use as oil additives. (See Divisions Cl, C3, C5 and C7).