Acid-catalyzed aldol-Meerwein–Ponndorf–Verley-etherification reactions—access to defined configured quaternary stereogenic centers

Absolute Stereochemistry of TXIB, a Bioactive Plasticizer That Inhibits Oviposition of the Peach Fruit Moth, Carposina sasakii (Lepidoptera: Carposinidae)

TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), a common plasticizer, inhibits the peach fruit moth, Carposina sasakii from ovipositing on young apple fruits. Using an insect assay and gas chromatography with an electroantennographic detector (GC-EAD) analysis, the stereochemistry of the bioactive compound was identified to be 3R, whereas (3S)-TXIB showed no activity. The inactive enantiomer did not inhibit the activity of commercially available TXIB, which was a racemic mixture. When the female moth was placed on the TXIB-treated fruits in the oviposition assay, she repeated grooming antennae. The reason why the moth detects this artificial compound is unknown, although the stereochemical structure of TXIB could have given an abnormality to the moth's antennae.

Scandium Triflate Catalyzed Tandem Transfer Hydrogenation and Cyclization Reaction of o-Aminobenzaldehydes and o-Aminoacetophenone with Alcohols

An effective Sc-catalyzed transfer hydrogenation and cyclization tandem reaction has been achieved. This process showed excellent functional group compatibility and good yields. A variety of benzoxazines were produced with primary or secondary alcohols as a hydrogen source. Furthermore, the utility of this newly developed protocol is demonstrated through scaled-up experiment, late-stage modification, and preliminary exploration of enantioselective synthesis.

Catalytic asymmetric Meerwein–Ponndorf–Verley reduction of glyoxylates induced by a chiral N,N′-dioxide/Y(OTf)3complex

An asymmetric MPV reduction of glyoxylates was for the first time achieved with excellent results and the mechanism of the reaction was probed.