Staudinger reduction reaction

Scheme 7.6. Synthesis of (-)-vasicinone (7-15) by a domino Staudinger-reduction/aza-Wittig reaction.

Staudinger reduction/aza-Wittig/Ugi three component reaction... 

NaBH(OAc)3 Staudinger reduction followed by aza-Wittig reaction, then reduction... 

Staudinger reduction/aza-Wittig/Ugi three component reaction 2 -trimethyls ilylethoxymethoxy single-electron transfer Shell Higher Olefin Process... 

Azides react with tertiary phosphines under mild conditions to form iminophosphoranes (1), which are versatile synthetic intermediates that have found a number of applications.1- 0 Upon treatment with water, an iminophosphorane will hydrolyze to form a primary amine and phosphine oxide in what is referred to as the Staudinger reaction or Staudinger reduction. 

One of the reasons that the Staudinger reduction is such a powerful synthetic tool is the fact that azides can be introduced into a molecule fairly easily.1-2 In fact, some of the improvements to the Staudinger reduction over the years have included many one-pot protocols converting alkyl bromides, alkyl chlorides, alcohols, and acetates to azides followed by the in situ reduction to the corresponding amines using the Staudinger reaction. 

Carbamates are one of the most widely used protecting groups for amines and the development of one-pot conversions of azides to carbamates such as Boc, Cbz, and allyl further expanded the scope of utility of the Staudinger reduction. Treatment of the Staudinger reaction iminophosphorane intermediate 26 with 1.05 equivalents of 2-t-(butoxycarbonyloximino)-2-phenylacetonitrile (Boc-on) led to Boc-protected amines 28 thru 32 in 87-100% overall yield.19 This process utilizes trimethylphosphine, which is more reactive than triphenylphosphine and provides an easier work-up because trimethylphosphine oxide is water soluble. It should be noted that the use of di-f-butyldicarbonate (B0C2O) has been investigated but leads to lower yields in comparison.20... 

The Blum aziridine isomerization describes the net coversion of epoxides 1 into N-H aziridines 3 via an intermediate azido-alcohol 2. The reaction proceeds by opening of the epoxide with an azide source followed by the Staudinger reduction and cyclization of the intermediate azido-alcohol to give the aziridine. The reaction proceeds with net inversion of stereochemistry around the epoxide. 

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