Intramolecular Aryne–Ene Reaction: Synthetic and Mechanistic Studies
作者:David A. Candito、Jane Panteleev、Mark Lautens
DOI:10.1021/ja205405n
日期:2011.9.14
chemistry of arynes is well developed, some challenges still remain. The ene reaction of arynes has not gained widespread use in synthesis as a result of poor yields and selectivity. A general, high yielding and selective intramolecular aryne-ene reaction is described providing various benzofused carbo- and heterocycles. Mechanistic data is presented, and a rationale for the resulting stereochemistry is
We report the ligand‐enabled C−H activation/olefination of freecarboxylicacids in the γ‐position. Through an intramolecular Michael addition, δ‐lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium‐catalyzed activation of freecarboxylicacids in the γ‐position. The developed protocol features a wide range of acid substrates and olefin
Preparation of polycyclic compounds by intramolecular photospirocyclization and photocycloaddition reactions of 4-alkenyl-1-cyanonaphthalene derivatives
Photoreactions of 5-phenyl derivatives produce a product having tricyclo[6.3.0.01,4]undecadiene skeleton. Formation of angulartriquinanes takes place in photoreactions of cycloalkene-linked cyanonaphthalenes. The observation demonstrates that π–π arene ring interactions, steric hindrance, and suitable locations of reaction sites in syn and anti singlet exciplexes govern the modes followed in intramolecular photoreactions
Catalytic 1,4-Rhodium(III) Migration Enables 1,3-Enynes to Function as One-Carbon Oxidative Annulation Partners in CH Functionalizations
作者:David J. Burns、Hon Wai Lam
DOI:10.1002/anie.201406072
日期:2014.9.8
1,3‐Enynes containing allylic hydrogens cis to the alkyne are shown to act as one‐carbon partners, rather than two‐carbon partners, in various rhodium‐catalyzedoxidativeannulations. The mechanism of these unexpected transformations is proposed to occur through double CH activation, involving a hitherto rare example of the 1,4‐migration of a RhIII species. This phenomenon is general across a variety
Development of an Intramolecular Aryne Ene Reaction and Application to the Formal Synthesis of (±)-Crinine
作者:David A. Candito、Dennis Dobrovolsky、Mark Lautens
DOI:10.1021/ja306881u
日期:2012.9.19
A general and high yielding annulation strategy for the synthesis of various carbo- and heterocycles, based on an intramolecular aryne ene reaction is described. It was found that the geometry of the olefin is crucial to the success of the reaction, with exclusive migration of the trans-allylic-H taking place. Furthermore, the electronic nature of the aryne was found to be important to the success