Showing papers by "David A. Nicewicz published in 2008"

Merging Photoredox Catalysis with Organocatalysis: The Direct Asymmetric Alkylation of Aldehydes

Abstract: Photoredox catalysis and organocatalysis represent two powerful fields of molecule activation that have found widespread application in the areas of inorganic and organic chemistry, respectively. We merged these two catalysis fields to solve problems in asymmetric chemical synthesis. Specifically, the enantioselective intermolecular α-alkylation of aldehydes has been accomplished using an interwoven activation pathway that combines both the photoredox catalyst Ru(bpy)3Cl2 (where bpy is 2,2′-bipyridine) and an imidazolidinone organocatalyst. This broadly applicable, yet previously elusive, alkylation reaction is now highly enantioselective and operationally trivial.

Self-consistent synthesis of the squalene synthase inhibitor zaragozic acid C via controlled oligomerization.

Abstract: Despite the prevalence of repeating subunits in chiral natural products, stereocontrolled oligomerization is a largely unexplored strategy for construction of carbon skeletal frameworks. This report describes the use of silyl glyoxylates as dipolar glycolic acid synthons in a controlled oligomerization reaction for the efficient construction of the squalene synthase inhibitor zaragozic acid C. This new methodology allows rapid, stereocontrolled formation of the carbon skeleton with a desirable protecting group scheme while minimizing functional group repair and oxidation state manipulations.

Tert‐Butyl Tert‐Butyldimethylsilylglyoxylate: A Useful Conjunctive Reagent

Abstract: Sodium azide N-Acetylsulfanilyl choride 4-Acetamidobenzenesulfonyl azide Tert-Butyl acetoacetate Tetrabutylammonium bromide Tert-Butyl diazoacetate N,N-Diisopropylethylamine Oxone ® monopersulfate Keywords: silylglyoxylates; conjunctive reagent; ozonolysis; oxo transfer; condensation; waste disposal