A non-dissociative open-flask hydroboration with ammonia borane: ready synthesis of ammonia-trialkylboranes and aminodialkylboranes.

Under open-flask conditions, ammonia borane hydroborates olefins in refluxing tetrahydrofuran. Unlike conventional hydroboration, the Lewis base (ammonia) is not dissociated from the boron center. Terminal alkenes selectively provide ammonia-trialkylborane complexes.

The first synthesis of a borylated α-methylene-γ-butyrolactone.

Background: The Michael acceptor scaffolding is a source of rich biological activity for α-methylene-γ-butyrolactones and their derivatives. A wide variety of these structures are present in many natural products that are well-known for their useful medicinal properties.

Results: The first example of a borylated α-methylene-γ-butyrolactone is presented herein, along with its antipancreatic cancer activities against Panc-1, MIA PaCa-2 and BXPC-3.