{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T03:04:49Z","timestamp":1790651089930,"version":"4.1.0"},"reference-count":106,"publisher":"Wiley","issue":"41","license":[{"start":{"date-parts":[[2014,8,28]],"date-time":"2014-08-28T00:00:00Z","timestamp":1409184000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2014,10,6]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>A solvent\u2010controlled cascade process has been identified for the dual purpose of the preparation of either dihydrocarbazoles or dihydropyridoindoles from identical N\u2010aryl\u2010\u03b1,\u03b2\u2010unsaturated nitrones and electron\u2010deficient allene starting materials. These reactions proceed smoothly under mild metal\u2010free conditions affording a range of two types of skeletally distinct indole\u2010based heterocycles in high yield and diastereoselectivity. These transformations demonstrate the use of a bifurcated cascade process that hinges on the ring\u2010opening event of a benzazepine intermediate for the synthesis of skeletally diverse heterocyclic products and rapid access to biologically\u2010significant, indole\u2010based structures.<\/jats:p>","DOI":"10.1002\/chem.201403268","type":"journal-article","created":{"date-parts":[[2014,8,28]],"date-time":"2014-08-28T11:34:39Z","timestamp":1409225679000},"page":"13217-13225","source":"Crossref","is-referenced-by-count":54,"title":["Solvent\u2010Controlled Bifurcated Cascade Process for the Selective Preparation of Dihydrocarbazoles or Dihydropyridoindoles"],"prefix":"10.1002","volume":"20","author":[{"given":"Dong\u2010Liang","family":"Mo","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Donald J.","family":"Wink","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura L.","family":"Anderson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2014,8,28]]},"reference":[{"key":"e_1_2_6_1_2","unstructured":"For reviews of diversity\u2010oriented synthesis see:"},{"key":"e_1_2_6_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/9781118618110.ch1"},{"key":"e_1_2_6_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/tcr.20144"},{"key":"e_1_2_6_4_2","doi-asserted-by":"publisher","DOI":"10.1039\/c2cs35023h"},{"key":"e_1_2_6_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms1081"},{"key":"e_1_2_6_6_2","unstructured":"For reviews of cascade reactions see:"},{"key":"e_1_2_6_7_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200601872"},{"key":"e_1_2_6_7_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200601872"},{"key":"e_1_2_6_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2007.03.158"},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1039\/b903290h"},{"key":"e_1_2_6_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar200338s"},{"key":"e_1_2_6_11_2","doi-asserted-by":"publisher","DOI":"10.2174\/138527211798109231"},{"key":"e_1_2_6_12_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.201300201"},{"key":"e_1_2_6_13_2","unstructured":"For recent examples of reagent\u2010 substrate\u2010 and catalyst\u2010controlled divergent cascade processes see:"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo400275p"},{"key":"e_1_2_6_15_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201202161"},{"key":"e_1_2_6_15_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201202161"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201103567"},{"key":"e_1_2_6_16_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201103567"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/co400022r"},{"key":"e_1_2_6_18_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.201000853"},{"key":"e_1_2_6_19_2","doi-asserted-by":"publisher","DOI":"10.1039\/c1sc00371b"},{"key":"e_1_2_6_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo400125p"},{"key":"e_1_2_6_21_2","doi-asserted-by":"publisher","DOI":"10.1039\/B917965H"},{"key":"e_1_2_6_22_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201201157"},{"key":"e_1_2_6_22_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201201157"},{"key":"e_1_2_6_23_2","doi-asserted-by":"publisher","DOI":"10.1038\/nchem.1178"},{"key":"e_1_2_6_24_2","doi-asserted-by":"publisher","DOI":"10.1039\/c3cc45289a"},{"key":"e_1_2_6_25_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo401210r"},{"key":"e_1_2_6_26_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201102440"},{"key":"e_1_2_6_26_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201102440"},{"key":"e_1_2_6_27_2","doi-asserted-by":"publisher","DOI":"10.1039\/b717635j"},{"key":"e_1_2_6_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201301963"},{"key":"e_1_2_6_28_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201301963"},{"key":"e_1_2_6_29_2","unstructured":"For examples of biologically active partially saturated carbazoles and pyrido[1 2\u2010a]indoles see:"},{"key":"e_1_2_6_30_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja0177049"},{"key":"e_1_2_6_31_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo2020246"},{"key":"e_1_2_6_32_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature10232"},{"key":"e_1_2_6_33_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja910695e"},{"key":"e_1_2_6_34_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja106284s"},{"key":"e_1_2_6_35_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo2025543"},{"key":"e_1_2_6_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/jm00385a022"},{"key":"e_1_2_6_37_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo070866o"},{"key":"e_1_2_6_38_2","unstructured":"For examples of solvent effects being used to halt cascade reactions see:"},{"key":"e_1_2_6_39_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200907076"},{"key":"e_1_2_6_39_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200907076"},{"key":"e_1_2_6_40_2","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.200700581"},{"key":"e_1_2_6_41_2","unstructured":"For reviews on the preparation of indoles due to interest in their biological activity see:"},{"key":"e_1_2_6_42_2","volume-title":"Alkaloids, Nature\u2019s Curse or Blessing","author":"Hesse M.","year":"2002"},{"key":"e_1_2_6_43_2","first-page":"75","volume-title":"The Alkaloids","author":"Bosch J.","year":"1996"},{"key":"e_1_2_6_44_2","doi-asserted-by":"publisher","DOI":"10.1021\/cr200447s"},{"key":"e_1_2_6_45_2","doi-asserted-by":"publisher","DOI":"10.1021\/np3000365"},{"key":"e_1_2_6_46_2","doi-asserted-by":"publisher","DOI":"10.1039\/a909834h"},{"key":"e_1_2_6_47_2","first-page":"752","volume":"12","author":"Edwankar C. R.","year":"2009","journal-title":"Curr. Opin. Drug Discovery Dev."},{"key":"e_1_2_6_48_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2011.06.040"},{"key":"e_1_2_6_49_2","unstructured":"This byproduct was later identified as2\u2009aas described in Table\u20055."},{"key":"e_1_2_6_50_2","unstructured":"For examples of cyclizations and cycloadditions of indoles for the synthesis of dihydrocarbazoles see:"},{"key":"e_1_2_6_51_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol4015199"},{"key":"e_1_2_6_52_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2011.05.014"},{"key":"e_1_2_6_53_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo901325d"},{"key":"e_1_2_6_54_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol060418n"},{"key":"e_1_2_6_55_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200601324"},{"key":"e_1_2_6_56_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4020(01)91317-1"},{"key":"e_1_2_6_57_2","doi-asserted-by":"publisher","DOI":"10.1039\/c39820000613"},{"key":"e_1_2_6_58_2","unstructured":"SiO2was excluded from the reaction of3\u2009nwith4\u2009ato minimize competing hydrolysis of the aldehyde\u2010derived nitrone."},{"key":"e_1_2_6_59_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol3022885"},{"key":"e_1_2_6_60_2","unstructured":"For related preparations of 2\u2010vinyl indoles and benzazepines from mixtures of nitrones and allenes see:"},{"key":"e_1_2_6_61_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4020(01)90291-1"},{"key":"e_1_2_6_62_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00273a018"},{"key":"e_1_2_6_63_2","doi-asserted-by":"publisher","DOI":"10.1055\/s-1994-22982"},{"key":"e_1_2_6_64_2","unstructured":"For a discussion of the regioselectivity of nitrone additions to electron\u2010poor allenes see:"},{"key":"e_1_2_6_65_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)84616-X"},{"key":"e_1_2_6_66_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00226a035"},{"key":"e_1_2_6_67_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00240a005"},{"key":"e_1_2_6_68_2","unstructured":"For related examples of 1 4\u2010additions of indoles see:"},{"key":"e_1_2_6_69_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00274a024"},{"key":"e_1_2_6_70_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00291a013"},{"key":"e_1_2_6_71_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja017255c"},{"key":"e_1_2_6_72_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo035552p"},{"key":"e_1_2_6_73_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja026936k"},{"key":"e_1_2_6_74_2","unstructured":"For an example of a non\u2010stereospecific [1 3]\u2010rearrangement of an exomethylene isoxazolidine see ref. [14c]."},{"key":"e_1_2_6_75_2","unstructured":"Run in the absence of silica gel and in the presence of Na2SO4to prevent hydrolysis of the aldehyde\u2010derived nitrones."},{"key":"e_1_2_6_76_2","unstructured":"The moderate yields observed for the aldehyde\u2010derived nitrones were due to competing hydrolysis of reactive intermediates."},{"key":"e_1_2_6_77_2","unstructured":"For related oxidations of tetrahydrocarbazoles see:"},{"key":"e_1_2_6_78_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tetlet.2004.08.175"},{"key":"e_1_2_6_79_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)99163-9"},{"key":"e_1_2_6_80_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja304767m"},{"key":"e_1_2_6_81_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo950990k"},{"key":"e_1_2_6_82_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00055a007"},{"key":"e_1_2_6_83_2","unstructured":"For related examples of retro\u2010Mannich openings of benzazepine intermediates leading to observation of hydrolysis products see ref. [13b]."},{"key":"e_1_2_6_84_2","unstructured":"For related examples of additions of \u03b1 \u03b2\u2010unsaturated aldehyde\u2010derived nitrones to allenes to form benzazepine intermediates which undergo retro\u2010Mannich reactions in cascade processes to form benzoindolizines see:"},{"key":"e_1_2_6_85_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(98)80051-8"},{"key":"e_1_2_6_86_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2009.03.076"},{"key":"e_1_2_6_87_2","unstructured":"When the transformation illustrated in Table\u20056 entry\u20057 was repeated in PhMe a mixture of1\u2009aand2\u2009awas observed: 51\u2009% 1\u2009a\/2\u2009a1:10 trans\/cis15:1). Yield and ratios determined by1H\u2005NMR spectroscopy and reference to CH2Br2. This suggests that although solvent is sufficient to change the pathway of the cascade process thiourea catalysts can also influence the chemoselectivity of the reaction."},{"key":"e_1_2_6_88_2","unstructured":"For examples of the synthesis of dihydropyrido[1 2\u2010a]indoles by substituted indole cyclizations or intramolecular Fischer\u2010Indole synthesis see:"},{"key":"e_1_2_6_89_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.19970030317"},{"key":"e_1_2_6_90_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo201955c"},{"key":"e_1_2_6_91_2","doi-asserted-by":"publisher","DOI":"10.1039\/c1gc15483d"},{"key":"e_1_2_6_92_2","unstructured":"Less than 5\u2009%1\u2009a\u20131\u2009nwere separated during purification of2\u2009a\u20132\u2009nindicating that the2:1ratios for all of these reactions were greater than or equal to 10:1."},{"key":"e_1_2_6_93_2","unstructured":"Less than 5\u2009%1\u2009o\u20131\u2009x 1\u2009bbwere separated during purification of2\u2009o\u20132\u2009x 2\u2009bbindicating that the2:1ratios for all of these reactions were greater than or equal to 10:1."},{"key":"e_1_2_6_94_2","unstructured":"Less than 5\u2009%6\u20138were separated during purification of25\u201327and less than 5\u2009% of the corresponding dihydrocarbazoles were separated from28\u201332indicating that the2:1ratios for all of these reactions were greater than or equal to 10:1."},{"key":"e_1_2_6_95_2","unstructured":"Irrespective of the reaction media amide substitution on the allene strongly favors the formation of dihydropyridoindoles and mixtures of1and2were even observed when these reagents were subjected to toluene\u2010mediated reaction conditions previously optimized for dihydrocarbazole synthesis."},{"key":"e_1_2_6_96_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.201000948"},{"key":"e_1_2_6_97_2","unstructured":"Allene4\u2009a(2\u2005equiv) was also added to the mixture of22\u2009aand5\u2009athat was heated to give2\u2009aand1\u2009ato remain consistent with the optimized reaction conditions which use an excess of allene4\u2009a."},{"key":"e_1_2_6_98_2","unstructured":"When the mixture of22\u2009aand5\u2009awere heated in the absence of23 analogous results to those described in Table\u20055 entry\u20059 were observed."},{"key":"e_1_2_6_99_2","unstructured":"Dihydrocarbazoles1and dihydropyridoindoles2have been stored for more than 6 months at \u221240\u2009\u00b0C with no change in the1H\u2005NMR spectrum. Dihydrocarbazoles1that have been prepared from ketone\u2010derived nitrones are stable in air at 25\u2009\u00b0C and only begin to oxidize slowly to the corresponding carbazoles at higher temperatures (5\u201310\u2009% after 18\u2005h at 80\u2009\u00b0C). Dihydrocarbazoles1that have been prepared from aldehyde\u2010derived nitrones are stable at \u221240\u2009\u00b0C but slowly oxidize at 25\u2009\u00b0C in air and more quickly at higher temperatures (\u223c50\u2009% after 18\u2005h at 80\u2009\u00b0C). Dihydropyridoindoles2show no sign of oxidation when heated in air for 18\u2005h at 80\u2009\u00b0C."}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.201403268","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.201403268","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T18:38:22Z","timestamp":1760294302000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.201403268"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,8,28]]},"references-count":106,"journal-issue":{"issue":"41","published-print":{"date-parts":[[2014,10,6]]}},"alternative-id":["10.1002\/chem.201403268"],"URL":"https:\/\/doi.org\/10.1002\/chem.201403268","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,8,28]]}}}