Search

Abstract: The first organocatalytic oxa-Diels–Alder reaction of acyclic α,β–unsaturated ketones with aldehydes is described. This reaction represents a highly chemo- and diastereoselective synthesis of substituted tetrahydropyran-4-ones in good yields with dr up to >95:5. [Copyright &y& Elsevier]

Abstract: A TMG catalyzed, practical and efficient hydrophosphorylation of 4-oxo-enoates by diethyl or diphenyl phosphite has been described. This protocol allows a convenient access to a variety of enol phosphates under mild conditions in good yield with excellent stereoselectivity. [Copyright &y& Elsevier]

Vinyl and ethynyl benzoxazinones have recently received increasing attention from organic chemists because they are powerful tools for the construction of structurally diverse aza -heterocycles. A number of catalytic cyclization reactions have been developed that used these two reagents and required the presence of a transition-metal catalyst (i.e., palladium, iron, and copper). This review highlights the design and synthesis of these versatile reagents, and their applications as precursors for transition-metal-containing 1,4-dipoles in dipolar cyclizations and related cascade reactions. The general mechanisms and asymmetric inductions are briefly discussed as well. [ABSTRACT FROM AUTHOR]

Abstract: An asymmetric formal [4+1] cycloaddition of camphor-derived sulfonium salts with aldimines has been described. The reaction allows for the efficient synthesis of trans-2,3-disubstituted-2,3-dihydrobenzofurans in moderate to good yields with >95:5 dr and up to 98% ee under mild reaction conditions. [Copyright &y& Elsevier]