ABSTRACT
The synthesis of a second-generation [6]-helicenoidal DMAP organocatalyst is reported. The synthesis is reliant upon a highly diastereoselective Rh-catalysed [2 + 2 + 2] triyne cycloisomerization, using an existing stereocentre to control the sense of forming helicity. Taken together, a scalable (>1 g), resolution-free entry to a helical DMAP with the capacity for subsequent functionalization, has been achieved.
ABSTRACT
The oxidation of alkyl and aryl aldehydes to their corresponding carboxylic acids has been achieved through the action of a biomimetic bridged flavin catalyst. The reaction uses readily available 35% aqueous hydrogen peroxide and is operationally simple. The oxidation is a green and sustainable reaction, obviating chlorinated solvents with minimal byproducts.
Subject(s)
Aldehydes/chemistry , Carboxylic Acids/chemistry , Biomimetics , Flavins/chemistry , Hydrogen Peroxide/chemistry , Molecular Structure , Oxidation-Reduction , Solvents/chemistryABSTRACT
The Ireland-Claisen [3,3]-sigmatropic rearrangement has been used to access biologically important ß,ß'-dihydroxy α-amino acids. The rearrangement reported is highly stereoselective and offers excellent levels of remote stereocontrol. This strategy has been used to synthesize the natural immunosuppressant mycestericin G and ent-mycestericin G, allowing for a revision of absolute configuration of this natural product.
