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For example, the synthesis of paracetamol typically requires three separate reactions. Divergent synthesis starts with a common intermediate, which branches into multiple final products through distinct reaction pathways. Convergent synthesis synthesis involves the combination of multiple intermediates synthesized independently to create a ...
In the synthesis of a sublibrary the support is not divided and only one amino acid is coupled to the whole sample. As a result, one position is really occupied by the same amino acid in all components. For example, in the B2 sublibrary position 2 is occupied by the "yellow" amino acid in all the nine components.
The Ugi reaction has been applied in combination with an intramolecular Diels-Alder reaction [16] in an extended multistep reaction. A reaction in its own right is the Ugi–Smiles reaction with the carboxylic acid component replaced by a phenol. In this reaction the Mumm rearrangement in the final step is replaced by the Smiles rearrangement. [17]
In another example, the Nicolaou's total synthesis of Taxol uses this reaction, although coupling stops with the formation of a cis-diol, rather than an olefin. Optimized procedures employ the dimethoxyethane complex of TiCl 3 in combination with the Zn(Cu). The first porphyrin isomer, porphycene, was synthesised by McMurry coupling. [8]
One example of a synthesis reaction is the combination of iron and sulfur to form iron(II) sulfide: + Another example is simple hydrogen gas combined with simple oxygen gas to produce a more complex substance, such as water.
This reaction has been used successfully to probe for azides in living systems, even though the reaction rate is somewhat slower than that of the CuAAC. Moreover, because the synthesis of cyclooctynes often gives low yield, probe development for this reaction has not been as rapid as for other reactions.
Trump last week demanded that BRICS member countries commit to not creating a new currency or supporting another currency that would replace the U.S. dollar, saying they would otherwise face 100% ...
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 ...