Basicity Of Nucleophile
Amines are essential for the building blocks of life; they are a key component in the formation of amino acids, proteins, and nucleic acids. Amines contain nitrogen that has one lone pair; this enables it to form 3 covalent bonds with other atoms, all while staying neutral. Due to an amines basicity, reaction with an acid is very easy and forms a positively charged ammonium ion. As well as being a strong base, amines are also quite good nucleophiles. When the nitrogen is directly attached to one or two R groups is more nucleophillic than when directly attached to a hydrogen atom. The reason behind this is due to the electron donating ability of the alkyl group. However, the increasing strength of the nucleophile proves difficulty when added
to organic compounds, where it will attack the electrophile and yield undesired products. In order to prevent this from occurring, and to obtain the desired basic substitution product, one must use a method called reductive animation. This is done by reacting the amine with ketone or aldehyde; thus forming an imine. Once the intermediate imine is formed, the nitrogen molecule is unable to attack the carbonyl, and has lost its nucleophillic properties. This proves very helpful because no side reactions are able to occur, and the desired amine product can be obtained by the use of a reducing agent.
The goal of this experiment is to perform reductive animation between p-toluidine and vanillin, using NaBH4 as the reducing agent. This reaction is carried out through the use of green chemistry. This is where the reaction is carried out under solvent free conditions. A mechanism for the formation of an imine is shown below:
to organic compounds, where it will attack the electrophile and yield undesired products. In order to prevent this from occurring, and to obtain the desired basic substitution product, one must use a method called reductive animation. This is done by reacting the amine with ketone or aldehyde; thus forming an imine. Once the intermediate imine is formed, the nitrogen molecule is unable to attack the carbonyl, and has lost its nucleophillic properties. This proves very helpful because no side reactions are able to occur, and the desired amine product can be obtained by the use of a reducing agent.
The goal of this experiment is to perform reductive animation between p-toluidine and vanillin, using NaBH4 as the reducing agent. This reaction is carried out through the use of green chemistry. This is where the reaction is carried out under solvent free conditions. A mechanism for the formation of an imine is shown below: