Oxidative Coupling of NH Isoquinolones with Olefins Catalyzed by Rh(III)

Abstract

Rh(III)-catalyzed oxidative coupling reactions between isoquinolones with 3-aryl groups and activated olefins have been achieved using anhydrous Cu(OAc)(2) as an oxidant to give tetracyclic products. The nitrogen atom acts as a directing group to facilitate ortho C-H activation. This reaction can be one-pot starting from methyl benzohydroxamates, without the necessity of the isolation of isoquinolone products. A broad scope of substrates has been demonstrated, and both terminal and internal activated olefins can be applied. In the coupling of N-methylmaleimide, a Wacker-like mechanism was proposed, where backside attack of the NH group in isoquinolones is suggested as a key step. Selective C-H activation has also been achieved at the 8-position of 1-naphthol, leading to an olefination product.

A Combined Transition‐Metal‐Catalyzed and Photopromoted Process: Synthesis of 2,3‐Fused 4‐Phenylnaphthalen‐1‐yl Carboxylates from 1,7‐Diaryl‐1,6‐diynes

“…Thus, 1 was treated with diphenylacetylene (1 equiv) in the presence of [( p ‐cymene)RuCl 2 ] 2 (2 mol %) and Cu(OAc) 2 ⋅ H 2 O (2 equiv) in m ‐xylene at 80 °C for 23 h, affording 8,10‐dihydrobenzo[ de ]furo[3,4 h ]chromene derivative 24 in 68 % yield. The oxidative Heck‐type reaction of 1 was also performed using the protocol reported by Du, Li, and co‐workers (Scheme ) 32. In the presence of [Cp*RhCl 2 ] 2 (3 mol %) and Cu(OAc) 2 (2.2 equiv), 1 and ethyl acrylate (2 equiv) were heated in DMF at 100 °C for 1 h to afford the desired product 25 in 74 % yield.…”

Rh(III)- and Ir(III)-Catalyzed C–C Bond Cross Couplings from C–H Bonds

“…The final E-product results from β-H elimination (Scheme 3). Alternatively, if a polar directing group is applied, olefination-Michael cyclization takes place [40,67,68].…”

Oxidation and Reduction

“…Further, neither the N nor OH group acted as directing group for C−H activation in NH isoquinolone if 3-aryl group was absent. 153 The oxidative coupling of benzylamines and 1-naphthylmethylamine with internal alkynes in o-xylene under N 2 led to the formation of isoquinoline and benzo[h]isoquinoline derivatives, respectively. The reaction occurred through dehydrogenation and dehydrogenative cyclization, and addition of 1,4-diazabicyclo [2.2.2]octane (DABCO) improved the yield of the product.…”

“…Reduction of the alkene C=C double bond of inisatin-derived electron-deficient alkenes (153), to give (154), has been promoted in high yield (>99%) by alkylphosphanes in the presence of water; a plausible mechanism (Scheme 15) was proposed on the basis of deuterium labelling and DFT calculations. 321 Cyclic α-diketones (acenaphthenequinone, aceanthrenequinone, and N-alkylisatins) were deoxygenated by tris(diethylamino)phosphine in the presence of fullerene C 60 .…”