In
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
a convergent synthesis is a strategy that aims to improve the
efficiency
Efficiency is the often measurable ability to avoid making mistakes or wasting materials, energy, efforts, money, and time while performing a task. In a more general sense, it is the ability to do things well, successfully, and without waste.
...
of
multistep synthesis, most often in
organic synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...
. In this type of synthesis several individual pieces of a complex molecule are synthesized in stage one, and then in stage two these pieces are combined to form the final product. 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 and involves fragment coupling and independent synthesis. This technique is more useful if the compound is large and symmetric, where at least two aspects of the molecule can be formed separately and still come together.
Examples:
* Convergent synthesis is encountered in
dendrimer
Dendrimers are highly ordered, Branching (polymer chemistry), branched molecules, polymeric molecules. Synonymous terms for dendrimer include arborols and cascade molecules. Typically, dendrimers are symmetric about the core, and often adopt a sph ...
synthesis where branches (with the number of generations preset) are connected to the central core.
* Proteins of up to 300
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...
s are produced by a convergent approach using
chemical ligation.
* An example of its use in
total synthesis
Total synthesis, a specialized area within organic chemistry, focuses on constructing complex organic compounds, especially those found in nature, using laboratory methods. It often involves synthesizing natural products from basic, commercially ...
is the final step (
photochemical
Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750&nb ...
+2 ycloaddition) towards the compound ''biyouyanagin A'':
[''Total Synthesis and Revised Structure of Biyouyanagin A'' K. C. Nicolaou, David Sarlah, and David M. Shaw Angew. Chem. Int. Ed. 2007, 46, 4708–4711 ]
:
See also
*
Divergent synthesis
References
Chemical synthesis
{{chemical synthesis