Intramolecular [4+2] cycloaddition of furfurylsubstituted homoallylamines to allylhalides, acryloyl chloride and maleic anhydride

Application of New Efficient Hoveyda–Grubbs Catalysts Comprising an N→Ru Coordinate Bond in a Six-Membered Ring for the Synthesis of Natural Product-Like Cyclopenta[b]furo[2,3-c]pyrroles

“…As we showed earlier [ 29 , 30 , 31 , 32 ], the synthesized 3-allyl-3a,6-epoxyisoindole-7-carboxylic acids 5 are excellent precursors for heterocyclization into the corresponding isoindoloquinolines and isoindolobenzazepines. In this process, the isomeric composition of adducts 5A/5B had no strong influence on the yield and stereochemistry of the target heterocycles.…”

“…Elucidation of the spatial structure of isomeric acids similar to 5A/5B and esters similar to 6A/6B has been previously done in the literature more than once [ 29 , 30 , 31 , 32 , 37 , 39 , 40 , 41 , 42 ], while as a rule, 2D NOE NMR data have been used for evidence of their structures. Here we present X-ray structural information for a pair of isomeric methyl esters 6eA/6eB , which confirms the preceding conclusions concerning the location of the substituent in the third position of the heterocyclic core ( Figure 3 ).…”

Crystal structures of the two epimers from the unusual thermal C6-epimerization of 5-oxo-1,2,3,5,5a,6,7,9b-octahydro-7,9a-epoxypyrrolo[2,1-a]isoindole-6-carboxylic acid, 5a(RS),6(SR),7(RS),9a(SR),9b(SR) and 5a(RS),6(RS),7(RS),9a(SR),9b(SR)

“…The intramolecular Diels-Alder furan (IMDAF) reaction between ,-unsaturated acid anhydrides and hydrogenated heterocycles, containing a furfurylamine moiety, has been studied for a long time (see, for example, Parker & Adamchuk, 1978;Blokzijl et al, 1991;Varlamov et al, 2006;Groenendaal et al, 2008;Nakamura et al, 2011;Zubkov et al, 2011Zubkov et al, , 2012Zubkov et al, , 2014Toze et al, 2015) and used for diastereospecific synthesis of diverse fused-ring systems. It is arguable that the pathway with a simultaneous controlled formation of four or five new stereogenic centers is the best approach to epoxyisoindoles and affords target adducts under mild conditions with satisfactory yields.…”

Expedient and Diastereoselective Synthesis of Substituted 6,6a-Dihydroisoindolo[2,1-a]quinolin-11(5H)-ones

“…4,5 Several procedures have been developed for the synthesis of dihydroisoindolo[2,1-a]quinolin-11(5H)-ones. [6][7][8][9][10][11][12][13][14][15][16][17] Pigeon et al reported the synthesis of 5,6-disubstituted isoindolo[2,1-a]quinolines via intramolecular acyliminium ion-olefin cyclization using p-toluenesulfonic acid. 6 Epsztajn et al reported the regioselective synthesis of isoindolo[2,1a]quinoline-5,11-diones from the corresponding carboxylic acid derivatives by intramolecular Friedel-Crafts acylation of the N-aryl ring using oxalyl chloride and AlCl 3 .…”

“…8 Later, they reported the same synthesis using polyphosphoric acid instead of phosphoric acid in the final cyclization step. 9 Zubkov et al reported the synthesis of substituted isoindolo[2,1-a]quinoline carboxylic acids via the intramolecular Diels-Alder reaction of 4-(Nfuryl-2)-4-arylaminobutenes-1 with maleic anhydride followed by cyclization using a mixture of phosphoric acid and sulfuric acid in a 3:1 ratio. 10 Zhang et al reported the synthesis of isoindolo[2,1-a]quinolin-11-ones from 2,3-dihydro-3-hydroxy-2-arylisoindol-1-ones and olefins in the presence of BF 3 •OEt 2 .…”