Orthogonal strategy

Bork J, Lee JW, Khersonsky SM, Moon HS, Chang YT, Novel orthogonal strategy toward solid-phase synthesis of 1,3,5-substituted triazines, Org. Lett., 5 117-120, 2003. 

Kates, S. A., Sole, N. A., Johnson, C. R., Hudson, D., Barany, G., and Albericio, F. (1993) A novel, convenient, three-dimensional orthogonal strategy for solid-phase synthesis of cyclic peptides. Tetrahedron Lett. 34, 1549-1552. 

The combination of two chemically distinct glycosylation reactions, in which one of the leaving groups is activated while the other one remains intact, and vice versa, has led to the discovery of the orthogonal strategy for oligosaccharide synthesis.4... 

A further orthogonal strategy compatible with peptide and many other organic synthesis is offered by allyl-functionalized anchors. The mechanism of release is depicted in Figure 5.8, and involves the use an intermediate Pd-complex with the double bond [267,268], Recent developments use Pd-catalyzed metathesis techniques to cleave unsaturated anchors in inter- and intramolecular reactions. An unsaturated tin-anchor has been used to achieve cleavage with an intramolecular Suzuki reaction. 

Scheme 7.1 Oligosaccharide assembly traditional concept (left) and by an orthogonal strategy (right).

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