Bobbitt reaction

The Bobbitt reaction is a name reaction in organic chemistry. It is named after the American chemist James M. Bobbitt. The reaction allows the synthesis of 1-, 4-, and N-substituted 1,2,3,4-tetrahydroisoquinolines and also 1-, and 4-substituted isoquinolines.

General Reaction Scheme
The reaction scheme below shows the synthesis of 1,2,3,4-tetrahydroisoquinoline from benzaldehyde and 2,2-diethylethylamine.



Reaction Mechanism
A possible mechanism is depicted below:



First the benzaliminoacetal 3 is built by the condensation of benzaldehyde 1 and 2,2-diethylethylamine 2. After the condensation the C=N-double bond in 3 is hydrogenated to form 4. Subsequently, an ethanol is removed. Next, the compound 5 is built including the cyclization step. After that the C=C-double bond in 5 is hydrogenated. Thus, 1,2,3,4-tetrahydroisoquinoline 6 is formed.

Applications
The Bobbitt reaction has found application in the preparation of some alkaloids such as carnegine, lophocerine, salsolidine, and salsoline.