Linker silicon-based

Plunkett MJ, Ellman JA. A silicon-based linker for traceless solid-phase synthesis. J Org Chem 1995 60 6006-6007. 

Chemistry similar to this was used in Ellman s paper to promote application of a silicon-based traceless linker.62 The full report on this work63 shows that both aliphatic and aromatic acid chlorides may be used in the coupling step. The same,approach is also shown to be successful with a germanium-based linker in place of the silicon. The couplings were typically performed for 1 h only, with equilibration time of a few minutes... 

Plunkett, M. J. Ellman, J. A. A Silicon-Based Linker for Traceless Solid-Phase Synthesis, J. Org. Chem. 1995, 60, 6006-6007. 

The silicon-based linker 1.10 (66), which can be readily prepared from commercially available PS-diethylsilane resin, has been successfully used to perform multistep SPS to give alcohols that could be cleaved with ACOH-THF-H2O in 4-8 h at 50 °C (48) or with HF.Py (hydrofluoric acid/pyridine complex) in THF at rt (67). 

There are only a few examples for germanium-based linkers in solid phase synthesis, hi general, the linker systems and the cleavage conditions are very similar to the silicon-based linkers that were introduced before. Two important germanium linkers are shown in Fig. 18. 

Silicon linker 76 was used for direct loading of aromatic compounds to supports for the assembly of pyridine-based tricyclics (Scheme 39) [87], Following the initial coupling of an aromatic bromide to the resin by halogen/metal exchange in the presence of tert-butyl lithium, a... 

F. X. Woolard, J. Paetsch, J. A. Ellman, A Silicon Linker for Direct Loading of Aromatic Compounds to Supports. Traceless Synthesis of Pyridine-Based Tricyclics , J. Org Chem. 1997, 62, 6102-6103. 

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