Redistribution in Combinatorial Synthesis. A Theoretical Approach

In modified versions of the split-mix method, the conventional solid support resin was replaced by labeled macroscopic support units in order to produce individual compounds in multi milligram quantities while the high productivity of the original procedure is preserved. Recently it has also been shown that tagging the units is unnecessary. Omission of the tags is possible if (i) the unlabeled support units are arranged into spatially ordered groups and the relative spatial arrangement of the units is maintained during the chemical reactions (ii) the support units are redistributed between the reaction steps according to a predetermined pattern permitted by the combinatorial redistribution rule and (iii) the sorting process is simulated by a computer that can trace the synthetic history of each support unit. Different kinds of solid support units, formation of spatially ordered groups, sorting devices and basic redistribution patterns (serial, semi-parallel and parallel) are discussed. It is also shown that particularly the semi-parallel and the parallel redistribution assure fast sorting.