Remote Electronic Effect of Chiral N-Heterocyclic Carbene Catalyst on an Asymmetric Benzoin Reaction.

A remote electronic effect of chiral aminoindanol-derived N-heterocyclic carbene catalyst on an asymmetric benzoin reaction was investigated. The catalyst bearing remote electron-withdrawing substituents increased enantioselectivity of the reaction at the cost of the reaction rate. DFT calculations rationalized the increased enantioselectivity.

Arabidopsis CYP85A2 catalyzes lactonization reactions in the biosynthesis of 2-deoxy-7-oxalactone brassinosteroids.

Brassinolide (BL), a plant 7-oxalactone-type steroid hormone, is one of the active brassinosteroids (BRs) that regulates plant growth and development. BL is biosynthesized from castasterone by the cytochrome P450 monooxygenase, CYP85A2. We showed that a Pichia pastoris transformant that synchronously expresses Arabidopsis P450 reductase gene ATR1 and P450 gene CYP85A2 converts teasterone and typhasterol to 7-oxateasterone and 7-oxatyphasterol, respectively.