A chiral phosphoric acid-catalyzed approach constructing dihydrocoumarin motifs by the addition of azlactones to para-quinone methides (p-QMs) was developed. The reaction proceeded smoothly with a wide range of p-QMs and azlactones to generate corresponding products in high yields with excellent diastereoselectivities (>19:1 dr) and enantioselectivities (up to 99% ee). Two possible pathways were proposed to explain the stereoselectivity.

Tris(pentafluorophenyl)borane has been found to catalyze the twofold C(sp 3)ÀH silylation of various trialkylamine derivatives with dihydrosilanes, furnishing the corresponding 4-silapiperidines in decent yields. The multi-step reaction cascade involves amine-to-enamine dehydrogenation at two alkyl residues and two electrophilic silylation reactions of those enamines, one inter-and one intramolecular.

A highly diastereoselective vinylogous nucleophilic 1,6-conjugate addition reaction of para-quinone methides with 3-propenyl-2-silyloxyindoles by a bismuth triflate catalyst has been developed. A number of diphenylmethane type compounds functionalized with oxindole motifs was obtained with excellent yields (up to 99%) and very good diastereoselectivities (up to Z/E > 99:1).

An aldehydew ith ac yclohexa-2,5-dienyl group in the a-position is introducedas as torable surrogate of highly reactivea cetaldehyde.T he cyclohexa-2,5-dienyl unit is compatible with an enantioselective Michael addition to nitroalkenes promoted by aH ayashi-Jørgensen catalysta nd can be removed by ab oron Lewis acid mediated CÀCb ond cleavage. The robust two-step sequence does not requirealarge excess of the aldehyde component that is typically neededw hen directly using acetaldehyde.

Readily available cyclohexa‐2,5‐dien‐1‐ylcarbonyl chloride derivatives are introduced as bench‐stable HCl surrogates for transfer hydrochlorination of terminal and internal alkenes as well as selected alkynes. The stepwise Grob fragmentation of those acyl chlorides into chloride, carbon monoxide, a low‐molecular‐weight arene, and a proton is promoted by B(C6F5)3. This decarbonylative transfer process enables the addition of HCl across C−C double and triple bonds with Markovnikov selectivity at room temperature.