Convergent synthesis

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In chemistry a convergent synthesis is a strategy that aims to improve the efficiency of multi-step chemical synthesis. In linear synthesis the overall yield quickly drops with each reaction step:

A → B → C → D

Suppose the yield is 50% for each reaction, the overall yield of D is only 12.5% from A.

In a convergent synthesis

A → B (50%)

C → D (50%)

B + D → E (25%)

the overall yield of E (25%) looks much better. Convergent synthesis is applied in the synthesis of complex molecules (see total synthesis) and involve fragment coupling and independent synthesis.

Example:

• Convergent synthesis is encountered in dendrimer synthesis ^[1] where branches (with the number of generations preset) are connected to the central core

• Proteins of up to 300 amino acids are produced by a convergent approach using chemical ligation.

See also: divergent synthesis

[edit] Reference

^[1] Convergent Synthesis of Internally Branched PAMAM Dendrimers Michael Pittelkow, Jrn B. Christensen Org. Lett., 7 (7), 1295 -1298, 2005