Catalytic control of reactions of dipoles and carbenes; an easy and efficient synthesis of cycloheptatrienes from aromatic compounds by an extension of Buchner's reaction

Gold-catalyzed naphthalene functionalization

“…Compounds 2b and 2c , respectively, are derived from the formal insertion of the carbene group into a C–H bond of naphthalene (Scheme 4). The selectivity observed is similar to that reported by Müller's group with [Rh 2 (O 2 CC 3 F 7 ) 4 ] (60:22:18) [8]. However, in our case the yield of products (EDA-based) was quantitative: products derived from dimerization of the diazo compound, i.e., diethyl fumarate and maleate, were not detected.…”

“…The above transformation with rhodium-based catalysts [ 7 – 8 ] has also been investigated with naphthalene as a substrate. In this case, Teyssié and co-workers showed that it could be converted, using t -butyl diazoacetate, into norcaradiene type derivatives, formed by the cyclopropanation of one of the double bonds of the naphthalene ring.…”

A study of the norcaradiene–cycloheptatriene equilibrium in a series of azulenones by NMR spectroscopy; the impact of substitution on the position of equilibrium

“…1,2 Mechanistically, it is believed that this ring expansion occurs via initial carbene addition to provide a norcaradiene 1N followed by reversible 6π electrocyclic ringopening to the more stable cycloheptatriene tautomer ‡ 1T with the equilibrium generally favouring the latter (Scheme 1). [4][5][6][7][8] Subsequent to the original work of Buchner, the existence of the norcaradiene tautomer was a topic of much dispute that was ultimately resolved in 1950s. [4][5][6][7][8] Subsequent to the original work of Buchner, the existence of the norcaradiene tautomer was a topic of much dispute that was ultimately resolved in 1950s.…”

“…3 While the earlier studies were conducted either thermally or photochemically, this transformation became practically useful from a synthetic perspective with the advent of rhodium carboxylate catalysts in the 1980s. [4][5][6][7][8] Subsequent to the original work of Buchner, the existence of the norcaradiene tautomer was a topic of much dispute that was ultimately resolved in 1950s. 3 The existence of the norcaradiene tautomer has also been irrefutably confirmed through trapping of this species in cycloaddition reactions and struc-tural characterisation of the cycloadducts, for example by Vogel, 9 Manitto 10 and Doyle.…”

Formation of Macrocycles by Catalytic Intramolecular Aromatic Cycloaddition of Metal Carbenes to Remote Arenes

“…[1][2][3] Intermolecular reactions of ethyl diazoacetate with monosubstituted benzenes produce two or more cycloheptatriene carboxylates with substituent-dependent regiocontrol. 4,5 Intramolecular aromatic cycloaddition reactions of diazocarbonyl compounds provide facile entry into bicyclo[5.n.0] systems, [6][7][8][9] but ring sizes have been limited to n ) 3 or 4. [1][2][3] Recently, the feasibility of macrocyclization in metal carbene transformations has been demonstrated in intramolecular cyclopropanation reactions of selected diazoacetates having double bonds sufficiently remote from the carbene center to form cyclopropane-fused 11-to 13membered rings.…”