Synthesis of sceptrin alkaloids.

[reaction: see text] A concise synthetic route to the marine alkaloids (+/-)-sceptrin and (+/-)-dibromosceptrin has been developed.

Carbon nucleophiles in the Mitsunobu reaction. Mono- and dialkylation of bis(2,2,2-trifluoroethyl) malonates.

[formula: see text] Simple dialkyl malonate esters, for example diethyl malonate, exhibit relatively limited scope as carbon nucleophiles in the Mitsunobu dehydrative alkylation reaction. In contrast, bis(2,2,2-trifluoroethyl) malonate readily undergoes dehydrative alkylation with primary alcohols, and using only a slight excess of malonate gives monoalkylated product in good yield. Some secondary alcohols can also be employed, and bis(2,2,2-trifluoroethyl) malonates can be used in a second dehydrative alkylation to give dialkylated products in good to excellent yield.

Controlling mode selectivity in palladium-catalyzed bisdiene carbocyclizations: optimizing for cyclization-trapping over cycloisomerization.

[reaction: see text] Screening combinations of five catalyst precursors with 13 phosphorus ligands identified cyclization catalysts that favor carbocyclization-trapping with N-hydroxyphthalimide over a competing cycloisomerization mode.