Bobbitt reaction explained

The Bobbitt reaction is a name reaction in organic chemistry. It is named after the American chemist James M. Bobbitt.[1] 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,[2] lophocerine, salsolidine, and salsoline.

See also

Notes and References

  1. Book: Wang. Zerong. Comprehensive organic name reactions and reagents. 2009. John Wiley. Hoboken, N.J.. 978-0-471-70450-8. 441–444.
  2. Bobbitt . James M. . Roy . Dibyendu Nath . Marchand . Anthony . Allen . Christopher Whitney . Synthesis of isoquinolines. VI. N-alkyl-1,2,4-tetrahydroisoquinolines . . 32 . 7 . 1967 . 2225–2227 . 10.1021/jo01282a030. .