Danheiser annulation

The Danheiser annulation, also known as the Danheiser TMS-cyclopentene annulation, is an organic reaction involving an α,β-unsaturated ketone and a trialkylsilylallene, typically in the presence of a Lewis Acid. This reaction results in the formation of five-membered rings[1]. The reaction was developed by Rick L. Danheiser, who is currently the Arthur C. Cope Professor of Chemistry at MIT[2].

The Danheiser annulation is a [3+2] annulation, meaning it involves the combination of a three-atom component and a two-atom component to form a five-membered ring. This reaction has been used to synthesize a variety of five-membered carbocyclic and heterocyclic systems[9].

The reaction is named after Rick L. Danheiser, who has also developed other popular methodologies for the synthesis of aromatic and dihydroaromatic compounds based on cycloadditions of highly unsaturated conjugated molecules[2].

It's important to note that the Danheiser annulation should not be confused with the Danheiser benzannulation, which is a different chemical reaction used in organic chemistry to generate highly substituted phenols in a single step[4].

Citations:

[1] https://en.wikipedia.org/wiki/Danheiser_annulation

[2] https://link.springer.com/chapter/10.1007/978-3-319-03979-4_81

[3] https://www.researchgate.net/publication/300159008_Danheiser_annulation

[4] https://en.wikipedia.org/wiki/Danheiser_benzannulation

[5] https://pubmed.ncbi.nlm.nih.gov/12123352/

[6] https://pubs.acs.org/doi/abs/10.1021/ja00310a109

[7] https://baranlab.org

[8] https://www.nsf.gov/awardsearch/showAward?AWD_ID=1464799

[9] http://web.mit.edu/chemistry/rld/methods/3+2organosilanes.html

[10] https://onlinelibrary.wiley.com/doi/10.1002/9780470638859.conrr177

[11] https://www.youtube.com/watch?v=Sj-Tx-WA--I

[12] https://synarchive.com/named-reactions/danheiser-annulation

[13] https://pubs.acs.org/doi/10.1021/ja00164a033