The Morita−Baylis−Hillman (MBH) reaction is a versatile C−C bond-forming reaction between an activated alkene and a carbon electrophile, commonly facilitated by a nucleophilic catalyst.1 Among the synthetic approaches for the construction of dibenzocycloheptanes via oxidative coupling or annulation strategy, required stoichiometric amount of the reagents. On the other hand, Typical IMBH processes provide access to five- and six-membered ring systems. Thus, there is a genuine requirement to develop a metal-free and catalytic strategy for dibenzocycloheptene moiety, which is the primary structural motif in several bioactive natural products and pharmaceutically relevant compounds like allocolchicine, metasequirine B, tenuifolin, etc.2
Herein, we disclose the first phosphine-catalysed IMBH reaction that provides ready access to highly functionalised dibenzo-fused cycloheptenones. An array of synthetically challenging 3-hydroxy2-arylidine-dibenzocyclohepten-1-ones could be assembled in good to excellent yields. The method is manipulated to access chiral dibenzocycloheptanes where axially chiral substrates were converted to a wide range of chiral dibenzocycloheptanes, possessing two chiral elements, axial and central chirality (scheme 1).3

Annulative Morita–Baylis–Hillman reaction to synthesise chiral dibenzocycloheptanes

In order to view the entire gallery of posters, videos, and other materials, please click "Submissions" below. 

To find the Q&A for each poster category, please click "Sessions" below. 

To ask a question, simply click on the session of interest. You will see a list of video presentations to the right. Below each video area, you'll see a section entitled 'Q&A for this presentation'. Here you can post questions to the presenters. They will be notified, and you'll also be notified when they reply to your question. You can expect that notification by email, and you'll find the author's response here.

27th CRSI National Symposium in Chemistry

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.