223751-33-5Relevant academic research and scientific papers
Enantioselective palladium catalyzed conjugate additions of ortho-substituted arylboronic acids to β,β-disubstituted cyclic enones: Total synthesis of herbertenediol, enokipodin A and enokipodin B
Buter, Jeffrey,Moezelaar, Renee,Minnaard, Adriaan J.
supporting information, p. 5883 - 5890 (2014/08/05)
The palladium-catalyzed conjugate addition (Michael addition) of ortho-substituted arylboronic acids to β,β-disubstituted cyclic enones, in particular 3-methyl cyclopent-2-enone and 3-methyl cyclohex-2-enone, is reported. With an achiral bipyridine-based palladium catalyst, good yields are obtained with a variety of ortho-substituted arylboronic acids. In the asymmetric version, good to very high enantiomeric excesses (up to 99% ee) are obtained, though the yields are moderate. The decreased yields are attributed to significant protodeboronation of the arylboronic acid. The developed methodology allows the efficient enantioselective synthesis of the very crowded, biologically active, sesquiterpenes herbertenediol, enokipodin A, and enokipodin B. This journal is the Partner Organisations 2014.
Total syntheses of (-)-herbertenediol, (-)-mastigophorene A, and (-)- mastigophorene B. Combined utility of chiral bicyclic lactams and chiral aryl oxazolines
Degnan, Andrew P.,Meyers
, p. 2762 - 2769 (2007/10/03)
A nonracemic bicyclic lactam has been used to construct a chiral cyclopentane containing vicinal quaternary carbon centers in optically pure form, which is common to all of the title compounds. An oxazoline-mediated asymmetric Ullmann coupling was then utilized to establish chirality about the biaryl axis of mastigophorenes A and B. Through the course of this synthesis, it was clearly demonstrated that smaller chiral auxiliaries lead to higher levels of atroposelection, a previously unknown phenomenon of the asymmetric Ullmann coupling.
