Hydroxyalkyl azides

Intermolecular Schmidt reactions of alkyl azides and hydroxyalkyl azides with cycloketones in the presence of a Lewis acid, lead to formation of iV-alkyl lactams and A-hydroxyalkyl lactams respectively in good yield. The synthesis of chiral lactams by an asymmetric Schmidt reaction has also been reported. ... 

In 2007, Aube reported the application of the synthesis of oxazolines and dihydrooxazines libraries using resin-bound scavengers via two methods [60]. In the first method, a polymer-bound PPh3 scavenger was used to scavenge excess hydroxyalkyl azide. Alternatively, a polymer-bound tosyl hydrazine was used to scavenge excess aldehyde (Scheme 8.45). 

Rearrangements. Cyclic ketones undergo ring expansion on reaction with hydroxyalkyl azides." Regioselectivity is dependent on steric and electronic factors. Beckmann rearrangement of ketoxime carbonates has been observed at room temperature. 

Scheme 4.6 Tntermolecnlar Schmidt reactions using hydroxyalkyl azides.

Variation 4 Asymmetric Schmidt Reaction of Ketones with Hydroxyalkyl Azides (Aube )... 

Schmidt Rearrangement Reactions with Alkyl Azides 201 Table 7.3 Reactions of hydroxyalkyl azides with ketones... 

Scheme 7.15 Asymmetric Schmidt reactions with a monosubstituted hydroxyalkyl azide...

Schmidt Rearrangements of Hydroxyalkyl Azides toward Biologically Relevant Compounds... 

A modular synthesis of a series of y-tum mimics was enabled by the Lewis acid-mediated reactions of enantiopnre hydroxyalkyl azides with piperidinones. This involved the preparation of enantiopnre azides 103, the side chains of which corresponded to those in natnrally occnrring side amino acids. These azides were combined with piperidinones 102 in the presence of BFs-OEta or TfOH, and the resulting imininm ethers hydrolyzed to the corresponding lactams 104 (Table 7.10). 

An additional library was synthesized using the same reaction of hydroxyalkyl azides with aldehydes originally reported by Boyer in 1955 (Scheme 7.3, Section 7.1). Thus, a library of oxazolines and dihydrooxazmes was synthesized from aromatic aldehydes and azides by treatment with BF3-OEt2 followed by capture of the excess aldehyde (or azide, not shown) with a resin bound scavenger (Scheme 7.53). ... 

Rudy H, Cramer KE (1939) Uber den oxydativen Abbau des alloxan-2-dimethylatino anils zu 1-methyl benzimidazol. Chem Ber A 72(4) 728-744 Sahasrabudhe K, Gracias V, Furness K, Smith BT, Katz CE, Reddy DS, Aube J (2003) Asymmetric Schmidt reaction of hydroxyalkyl azides with ketones. J Am Chem Soc 125 (26) 7914-7922. doi 10.1021/ja0348896... 

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