Mdw

To design a traceless linker one must start from a heteroatom-carbon bond which is labile towards protogenolytic, hydrogenolytic, or hydridolytic cleavage.

Because most heteroatom-carbon single bonds are less stable than carbon-carbon bonds, traceless linkers can be synthesized on the basis of nearly all heteroatoms. The enthalpies of C-X bonds are, however, only relevant for homolytic bond scission. Many linkers are cleaved heterolytically, and kinetic stability toward hetero-lytic bond cleavage is decisive in these linkers.

The most prominent anchors for traceless linkage of arenes are based on silyl linkers. Generation of a diverse benzodiazepine library [40] has clearly shown the advantages of this type of detachment because no additional functionality, which might bias the library, was preserved in the final molecules (Scheme 6.1.33).

Me Me

R1COCl, Pd2(dba)3 Ge

NHMpc

R1COCl, Pd2(dba)3 Ge

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