TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The Lewis acid and Lewis base are separate molecules that together form the frustrated Lewis pair. The Lewis acid and Lewis base may be separate moieties of the same molecule. The Lewis acid has a structure of formula (L-X(Q1)-Q2) (I). The Lewis acid is tris(pentafluorophenyl)borane, tris(pentachlorophenyl)borane, bis(pentachlorophenyl)-(pentafluorophenyl)borane, (pentachlorophenyl)-bis(pentafluorophenyl)borane, tris(pentafluorophenyl)alane, tris(tetrafluorophenyl)borane, chloro-bis(pentafluorophenyl)borane, or borane compound of formula ((HB(C6F5)2)n). The Lewis base is pyridine compounds of formula (III), amine compounds of formula (R1g-C(R1e)(R1h)-N(R1k)-C(R1f)(R1i)-R1j) (IV), 2,3-dihydro-1H-imidazole radical of formula (V) or phosphane compounds of formula (R1x-P(R1y)(R1z)) (VI). The frustrated Lewis pair is 1-(2-(bis-pentafluorophenyl-boranyl)-benzyl)-2,2,6,6-tetramethyl-piperidine.(R1zR1yP-(CH2)2-B(C6H5)2) or a borane compound of formula (1a). The frustrated Lewis pair comprises tris(pentafluorophenyl)borane as the Lewis acid and a Lewis base comprising 2,6-dimethylpyridine, 2,6-di-tert-butylpyridine, 2,2,6,6-tetramethylpyridine, 1,3-ditert-butyl-2H-imidazole radical, tri-tolyl-phosphane, tris-(trimethyl-phenyl)-phosphane, ferrocene complexes of formula (a) or (b). The Lewis base is pyridine or 2,2,6,6-tetramethylpiperidine.X = Group 13 element such as B or Al;Q1, Q2 = hydrocarbyl, carbocyclyl, or heterocyclyl (all optionally substituted with one or more substituents of halo, CN, nitro, OH, 1-6C alkyl, 3-6C cycloalkyl, 1-6C alkoxy, phenyl, (1-6C)alkylphenyl, heterocyclyl, (1-6C)alkylheterocyclyl or a linker group which is capable of binding the X atom to a solid support), preferably phenyl (optionally substituted by F or CN);L = H, halo, any one of the groups Q1 or Q2, or a linker group which is capable of binding the X atom to a solid support;n = 1 or 2;R1a, R1b, R1c, R1d = substituent group other than hydrogen, or a linker group to connect (III) to a Lewis acid (e.g. -XQ1Q2) or solid support;w = 0-3;R1g, R1h, R1i, R1j = substituent group other than hydrogen, or one R1g, R1h, R1i and R1j is a linker that connects the Lewis base to a Lewis acid (e.g. -XQ1Q2) or a solid support; eitherR1e, R1f = 1-6C alkyl (optionally substituted with halo, nitro, CN, amino, CF3, 1-6C alkyl, 1-6C alkoxy, or -S(O)r-(1-6C)alkyl); orR1eR1f = (together with the -C(R1gR1h)-N(R1k)-C(R1iR1j)-) = 5, 6 or 7-membered heterocyclic ring (optionally comprising one or two additional heteroatoms of N, O or S, and optionally substituted with one or more substituent groups of halo, nitro, CN, amino, CF3, 1-6C alkyl, 1-6C alkoxy or -S(O)r-(1-6C)alkyl) or a Lewis acid (e.g. -XQ1Q2);r = 0-2;R1k = H, an optionally substituted ferrocene, or a linker that connects the Lewis base to a Lewis acid (e.g. -XQ1Q2) or a solid support;R1m, R1n = H or 1-6C alkyl;R1o, R1p = H, halo, nitro, CN, amino, CF3, 1-6C alkyl, 1-6C alkoxy, NH(1-6C)alkyl, N((1-6C)alkyl)2, -S(O)r-(1-6C)alkyl or aryl (e.g. phenyl), where one of R1m, R1n, R1o and R1p is a linker that connects the Lewis base to a Lewis acid (e.g. - XQ1Q2) or a solid support;R1x, R1y, R1z = hydrocarbyl (especially 1-6C alkyl e.g. methyl or tert-butyl), carbocyclyl (e.g. phenyl), heterocyclyl, or an optionally substituted ferrocene group (all optionally substituted with halo, CN, nitro, amino, aryl, heterocyclyl, 1-6C alkyl or 1-6C alkoxy), an optionally substituted ferrocene or a Lewis acid (e.g. -X Q1Q2) , where one of R1x, R1y and R1z is a linker group that comprises a functional group capable of connecting the phosphorus atom to a solid support. EXAMPLE - No preparative examples are given.