Which of the following reactions are chemoselective?
Which of the following reactions are chemoselective?
Chemoselective: A reaction that operates exclusively on one functional group in the presence of other functional groups. This NaBH4 reduction is chemoselective because the ketone is reduced but the ester is unchanged.
What is Chemoselectivity explain with example?
Chemoselectivity is the preferential outcome of a chemical reaction over a set of possible alternative reactions. Examples include the selective organic reduction of the greater relative chemoselectivity of sodium borohydride reduction versus lithium aluminium hydride reduction.
Which are chemoselective reagents?
If an organic compound contains more than one different functional groups or more than one like functional groups that are not equivalent (see equivalent ligands), and, if a reagent reacts exclusively or predominately with one of them, the reaction is said to be chemoselective.
What is stereoselective reaction with example?
An example of modest stereoselectivity is the dehydrohalogenation of 2-iodo-butane which yields 60% trans-2-butene and 20% cis-2-butene. Since alkene geometric isomers are also classified as diastereomers, this reaction would also be called diastereoselective.
What causes regioselectivity?
Since alkene addition reactions form bonds to two adjacent carbons, if the two new single bonds that are formed are to different atoms, we therefore have the potential to form isomers. …
What do you mean by asymmetric synthesis?
asymmetric synthesis, any chemical reaction that affects the structural symmetry in the molecules of a compound, converting the compound into unequal proportions of compounds that differ in the dissymmetry of their structures at the affected centre.
How do you describe regioselectivity?
Regioselective: Any process that favors bond formation at a particular atom over other possible atoms.
What causes Regioselectivity?
Why is a reaction not stereoselective?
The first reaction gives you two stereoisomers. Those are enantiomers. The first reaction gives no preference to one stereoisomer or the other. So, it’s NOT stereoselective.
How do you describe Regioselectivity?
What does high Regioselectivity mean?
Explanation: Regioselectivity is the preference in one region for a chemical bond making or breaking over all other possible regions. It’s a very common characteristic of specific reactions such as addition to piligands, or most addition reactions.
When is a reaction said to be chemoselective?
If an organic compound contains more than one different functional groups or more than one like functional groups that are not equivalent (see equivalent ligands ), and, if a reagent reacts exclusively or predominately with one of them, the reaction is said to be chemoselective.
When does a chemo selective reaction take place?
Chemo Selective Reactions: A reaction that operates exclusively on one functional group. In the presence of other functional groups is said to the chemoselective reaction. E.g.In this reaction when this compound is reduced with LiAlH4 and H3O+,…
Which is an example of a chemoselectivity epoxidation?
Chemoselective epoxidations of many alkenes carrying functional groups such as hydroxy, ether, ester, amide and ketone have been presented in this chapter. Chemoselective epoxidations of a few functionalized alkenes have proved difficult, but by using appropriate reagents and strategies the difficulties have been overcome.
Which is more effective, chemoselectivity or protecting groups?
Protecting groups can be used instead of chemoselectivity but with the disadvantage of having to perform two additional synthesis steps (protection and deprotection). However, if the reagent and reaction conditions are well chosen, the chemoselectivity can be more effective than protecting groups.
