Nucleosides. Part LXIII. Acetals as new 2?-O-protecting functions for the synthesis of oligoribonucleotides: Synthesis of uridine building blocks and evaluation of their relative acid stability
A broad variety of new acyclic vinyl ethers (see 6–41) have been synthesized via the vinyl-interchange reaction of ethyl vinyl ether at room temperature using mercury(II) trifluoroacetate as a highly efficient catalyst. The appropriate vinyl ethers were reacted under acidic conditions with 3′,5′-O-silyl-protected uridine 42 to the corresponding 2′-O-(1-alkoxyethyl) derivatives 43–83 which gave, on
Dynamic Kinetic Asymmetric [3 + 2] Annulation Reactions of Aminocyclopropanes
作者:Florian de Nanteuil、Eloisa Serrano、Daniele Perrotta、Jerome Waser
DOI:10.1021/ja5024578
日期:2014.4.30
asymmetric [3 + 2] annulation reaction of aminocyclopropanes with both enol ethers and aldehydes. Using a Cu catalyst and a commercially available bisoxazoline ligand, cyclopentyl- and tetrahydrofurylamines were obtained in 69-99% yield and up to a 98:2 enantiomeric ratio using the same reaction conditions. The method gives access to important enantio-enriched nitrogen building blocks for the synthesis of bioactive