The PGA Research Group

Haibo Wu

HW3

The main goal of my Ph.D. studies is to develop novel chiral Iridium catalysts and useful methodologies for asymmetric catalysis. Catalytic reactions featuring high efficiency (in terms of yield, selectivity, atom economy, etc) are powerful tools in organic synthesis, especially Iridium-catalyzed asymmetric reactions. Based on the significant achievements from our group in Ir-N,P complexes catalyzed asymmetric hydrogenation, this research involves design and synthesis of the new chiral Ir-N,P complexes to be employed as catalysts in asymmetric hydrogenation of a series of challenge olefins, such as 1,3- and 1,4-disubstituted 1,4-cyclohexadienes,  β-hydroxysilanes, tetrasubstituted alkenes, generating useful corresponding chiral products. Furthermore, through optimization, we hope to achieve good chemo and regioselective as well as highly enantioselective under specific reaction conditions.

During our previous research, we were surprised to find that theβ-hydroxysilane  substrates could be effectively hydrogenated by using our reported phosphite-oxazoline Iridium complexes as the catalysts. However, primary results showed that the enantiomeric excess of some difficult substrates still need to be improved even though the best catalyst was employed.

According to the previous investigation of the effect of systematically varying the substituents in the oxazoline moiety, a series of modified phosphite-oxazoline Iridium catalysts were designed and synthesized to investigate the asymmetric hydrogenation of β-hydroxysilane substrates and improved results already been achieved.

References

1. J.JohanVerendel, OscarPam`ies, Montserrat Dieg´uez,* andPher G. Andersson* Chem. Rev.2014, 114, 2130.
2. Margarita, C.; Andersson, P. G. J. Am. Chem. Soc. 2017, 139, 1346.
3. Jianguo Liu, Suppachai Krajangsri, Thishana Singh, Giulia De Seriis, Napasawan Chumnanvej, Haibo Wu, and Pher G. Andersson* J. Am. Chem. Soc.2017, 139, 14470