DIBAL-H-mediated -deacetylation of tertiary amides: synthesis of synthetically valuable secondary amines.

A rapid DIBAL-H-mediated -deacetylation of tertiary amides is described under mild conditions, affording synthetically valuable secondary amines in good to excellent yields.

N-Heterocyclic carbene-catalysed homoenolate addition reaction to 3-cyano-2-imino-2-chromenes: synthesis of C-functionalized 2-amino-3-cyano-4-chromene.

A diastereoselective N-heterocyclic carbene-catalysed reaction between enal and 3-cyano-2-imino-2-chromene is described for accessing a new type of C-functionalized 2-amino-3-cyano-4-chromene. A wide variety of enals and iminochromenes afforded the desired homoenolate addition product 2-amino-4-chromenes in good yields and with moderate to good diastereoselectivities.

HFIP-promoted halo-carbocyclizations of - and -tethered arene-alkene substrates to access all halo (X = Br, I, Cl)-functionalized tetrahydroquinoline and chroman cores.

A new method for the stereoselective metal-, additive- and oxidant-free Friedel-Crafts-type halo-carbocyclization of - and -tethered arene-olefin substrates is reported, involving reaction with a suitable electrophilic halogenating reagent (NXS/DCDMH) in hexafluoroisopropanol. All halo (X = Br, I, Cl)-functionalized tetrahydroquinolines and chromans were obtained in excellent yields and with high levels of diastereocontrol (dr = >99 : 1), and these products were successfully transformed into synthetically useful compounds such as dihydroquinolines and partial or full azahelicene compounds.