The Blum–Ittah aziridine synthesis, also known as the Blum–Ittah-Shahak aziridine synthesis or simply the Blum aziridine synthesis is a name reaction of organic chemistry, for the generation of aziridines from

oxiranes In organic chemistry, an epoxide is a cyclic ether () with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence highly reactive, more so than other ethers. They are produced on a large scale for ...

Mechanism

The oxirane is first converted into a 2-azidoalcohol with the use of an

azide In chemistry, azide is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant applic ...

such as sodium azide. The azido alcohol is then reduced with the use of a trialkylphosphine such as triphenylphosphine in a manner similar to the

Staudinger reaction The Staudinger reaction is a chemical reaction of an organic azide with a phosphine or phosphite produces an iminophosphorane. The reaction was discovered by and named after Hermann Staudinger. The reaction follows this stoichiometry: :R3P + ...

, concomitant with loss of N₂. The resulting phosphonimine (formerly called iminophosphorane) intermediate is then attacked by the alcohol, with oxygen forming a bond with the phosphorus atom. Forming a ring intermediate. After a proton transfer, a pair of electrons from the oxygen atom shifts onto the phosphorus atom, and the phosphorus-nitrogen bond breaks, with the electron pair shifting onto the nitrogen atom. The negatively charged nitrogen atom attacks the carbon atom that the oxygen atom is connected to. This gives us our desired aziridine and a trialkylphosphine oxide as a side product.

Applications

The Blum-Ittah aziridine synthesis has been used in the synthesis of α-methylserine and 6-Azabicyclo .2.1ctanes.

References

Name reactions Nitrogen heterocycle forming reactions {{Reaction-stub