Comparative studies of Nsc and Fmoc as N(alpha)-protecting groups for SPPS

Protecting groups are compounds that can bind to a specific functional group in the presence of other functional groups to protect them from undesired chemical reactions. These compounds can selectively bind to particular functional groups and advance chemoselective reactions in polyfunctional systems (Figure 1). After the functional group has served its purpose, it is removed by reacting it with specific compounds.

This lesson delves into the concept of protection and deprotection of a functional group fundamental to synthetic organic chemistry. These phenomena are explained in the context of aliphatic and aromatic alcohols.
Protection
It defines a protecting group as the masking agent to make the more reactive species inert to a given set of conditions. This concept is depicted via the illustration of liquid flow through different outlets in an assembly of pipes. The analogy helps to understand the role...

Acetals are formed by reacting two equivalents of alcohol with carbonyl compounds like aldehydes or ketones. Acetals are unaffected by bases, nucleophiles, oxidizing agents, and reducing agents. They serve as protecting groups for aldehydes and ketones. Acetals can be easily formed and also easily removed via mild acid hydrolysis.
In the presence of multiple functional groups, when selective reduction of one group over the other is desired, groups like aldehydes and ketones that form acetals...

Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of that molecule. For example, the presence of certain functional groups on a molecule will make them hydrophilic, whereas others will make them hydrophobic. These functional groups are an indispensable part of organic chemistry and important components of biological molecules, such as carbohydrates, proteins, lipids, and nucleic acids. Each...

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of that molecule. For example, the presence of certain functional groups on a molecule will make them hydrophilic, whereas others will make them hydrophobic. These functional groups are an indispensable part of organic chemistry and important components of biological molecules, such as carbohydrates, proteins, lipids, and nucleic acids. Each...