{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T10:03:25Z","timestamp":1789380205272,"version":"build-2803163510"},"reference-count":85,"publisher":"Wiley","issue":"38","license":[{"start":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T00:00:00Z","timestamp":1785024000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T00:00:00Z","timestamp":1785024000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["CHE\u20101048804"],"award-info":[{"award-number":["CHE\u20101048804"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Angew Chem Int Ed"],"published-print":{"date-parts":[[2026,9,14]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>A famous class of alkene\u2010containing compounds that have intrigued chemists for more than a century are anti\u2010Bredt olefins (ABOs). ABOs are a subclass of bridgehead alkenes that reside in small ring systems, thus rendering them unstable and historically challenging to leverage in chemical synthesis. The present study describes metal catalyzed reactions of a [2.2.1]\u2010bridged bicyclic ABO, wherein two in situ\u2010generated species, both present in low concentration and generated transiently, undergo a productive reaction. The transformation uses palladium catalysis to unite the aforementioned ABO with indole\u2010based trapping partners, thus delivering unusual heterocyclic products. The scope of the reaction is reported, as well as computations concerning the putative Pd\u2010bound ABO species. The latter suggests that the short\u2010lived ABO is stabilized by Pd via the energetically favorable formation of an intermediate palladacycle. This methodology is expected to prompt the further development of unconventional reactions, including metal\u2010catalyzed processes of ABOs and other transient olefins.<\/jats:p>","DOI":"10.1002\/anie.3724263","type":"journal-article","created":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T17:52:02Z","timestamp":1785088322000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Palladium\u2010Catalyzed Annulations of an Anti\u2010Bredt Olefin"],"prefix":"10.1002","volume":"65","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-5653-9737","authenticated-orcid":false,"given":"Zach G.","family":"Walters","sequence":"first","affiliation":[{"name":"Department of Chemistry and Biochemistry University of California  Los Angeles California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1396-2818","authenticated-orcid":false,"given":"Marie","family":"Deliaval","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Biochemistry University of California  Los Angeles California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-1182-8057","authenticated-orcid":false,"given":"Aimee","family":"Long","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Biochemistry University of California  Los Angeles California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7793-2629","authenticated-orcid":false,"given":"Neil K.","family":"Garg","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Biochemistry University of California  Los Angeles California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,26]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.chempr.2019.12.027"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/1521\u20103773(20010302)40:5<820::AID\u2010ANIE820>3.0.CO;2\u2010F"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201400932"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr00095a007"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr00097a013"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/jlac.19244370102"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1038\/s44160\u2010025\u201000776\u2010w"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00999a049"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja50001a061"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.197102621"},{"key":"e_1_2_8_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/hlca.19780610506"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00784a084"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00445a042"},{"key":"e_1_2_8_15_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00162a022"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00013a038"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja953977q"},{"key":"e_1_2_8_18_1","doi-asserted-by":"publisher","DOI":"10.1039\/b203580d"},{"key":"e_1_2_8_19_1","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201500131"},{"key":"e_1_2_8_20_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.adq3519"},{"key":"e_1_2_8_21_1","volume-title":"IUPAC Compendium of Chemical Terminology","year":"2025"},{"key":"e_1_2_8_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.197304641"},{"key":"e_1_2_8_23_1","unstructured":"Another common definition is as follows as described in Ref 21: \u201cBredt compounds are bicyclic (and polycyclic) systems (alicycles and heterocycles) that in addition to a strained \u03c3\u2010bond skeleton have a twisted \u03c0\u2010bond at a bridgehead and purely because of this ring strain in contrast with compounds having the same structure but without this \u03c0\u2010bond are unstable at room temperature.\u201d"},{"key":"e_1_2_8_24_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr60147a003"},{"key":"e_1_2_8_25_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00398a003"},{"key":"e_1_2_8_26_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00999a050"},{"key":"e_1_2_8_27_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00707a035"},{"key":"e_1_2_8_28_1","doi-asserted-by":"publisher","DOI":"10.1039\/D4SC06697A"},{"key":"e_1_2_8_29_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201503822"},{"key":"e_1_2_8_30_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.orglett.4c00879"},{"key":"e_1_2_8_31_1","doi-asserted-by":"publisher","DOI":"10.3390\/org5030010"},{"key":"e_1_2_8_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.elspec.2025.147553"},{"key":"e_1_2_8_33_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.5c22985"},{"key":"e_1_2_8_34_1","doi-asserted-by":"publisher","DOI":"10.1039\/D5RA09135G"},{"key":"e_1_2_8_35_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201909349"},{"key":"e_1_2_8_36_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.4c15004"},{"key":"e_1_2_8_37_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.6c06155"},{"key":"e_1_2_8_38_1","doi-asserted-by":"publisher","DOI":"10.1002\/ceur.70285"},{"key":"e_1_2_8_39_1","doi-asserted-by":"publisher","DOI":"10.1039\/D5SC03943F"},{"key":"e_1_2_8_40_1","doi-asserted-by":"publisher","DOI":"10.1246\/cl.1983.1211"},{"key":"e_1_2_8_41_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00179a050"},{"key":"e_1_2_8_42_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.chemrev.0c01011"},{"key":"e_1_2_8_43_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.checat.2022.06.014"},{"key":"e_1_2_8_44_1","doi-asserted-by":"publisher","DOI":"10.1055\/s\u20100036\u20101589517"},{"key":"e_1_2_8_45_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacsau.1c00214"},{"key":"e_1_2_8_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0022\u2010328X(00)81419\u20109"},{"key":"e_1_2_8_47_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00495a067"},{"key":"e_1_2_8_48_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr00089a004"},{"key":"e_1_2_8_49_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00062a071"},{"key":"e_1_2_8_50_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.198912961"},{"key":"e_1_2_8_51_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.adi1606"},{"key":"e_1_2_8_52_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.5b06576"},{"key":"e_1_2_8_53_1","unstructured":"Metal complexes of isolable bridgehead olefins (i.e. in larger ring systems) have been synthesized with Pd and Pt; see references 53 54 and 55. Isomerization reactions have also been reported; see reference 56."},{"key":"e_1_2_8_54_1","doi-asserted-by":"publisher","DOI":"10.1021\/om50003a035"},{"key":"e_1_2_8_55_1","doi-asserted-by":"publisher","DOI":"10.1021\/om00121a016"},{"key":"e_1_2_8_56_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.197906851"},{"key":"e_1_2_8_57_1","doi-asserted-by":"publisher","DOI":"10.1002\/hlca.19790620715"},{"key":"e_1_2_8_58_1","doi-asserted-by":"publisher","DOI":"10.1021\/om0503388"},{"key":"e_1_2_8_59_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr60301a002"},{"key":"e_1_2_8_60_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo060698k"},{"key":"e_1_2_8_61_1","unstructured":"OSE is calculated by comparing the strain energy of the strained intermediate to the strain energy of the saturated parent system (i.e.2to norbornane)."},{"key":"e_1_2_8_62_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja055781o"},{"key":"e_1_2_8_63_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo0619534"},{"key":"e_1_2_8_64_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo0614339"},{"key":"e_1_2_8_65_1","unstructured":"Strained intermediate precursors are often used in excess in transition metal\u2010catalyzed trappings due to their fleeting nature and the aforementioned kinetic challenges (see Figure 2 discussion)."},{"key":"e_1_2_8_66_1","unstructured":"Although the addition of Cs2CO3resulted in only a modest increase in yield it improved reaction reproducibility. We presume this is due to the presence of a more soluble base ensuring that acidic byproducts formed as part of the reaction mechanism are quickly neutralized."},{"key":"e_1_2_8_67_1","unstructured":"With regard to the mass balance of these annulations small quantities of proto\u2010dehalogenation are observed but the rest of the mass balance is attributed to nonspecific decomposition. In typical reactions 7is fully consumed whereas6is mostly consumed."},{"key":"e_1_2_8_68_1","unstructured":"The use of standard reaction conditions (Table 1 entry 5 conditions) in the presence of anthracene (15 equivalents) resulted in the formation of the corresponding known (4+2) cycloadduct instead of products8oriso\u20108; see the Supporting Information Section I.B for details."},{"key":"e_1_2_8_69_1","unstructured":"Although selectivity would be preferred there are some applications where having two products could be deemed advantageous (e.g. synthesis of analogs)."},{"key":"e_1_2_8_70_1","unstructured":"Although ratios of isomers obtained from annulation varied slightly between annulation partners reactions were generally unselective giving isomeric products in similar quantities."},{"key":"e_1_2_8_71_1","unstructured":"We envisioned that steric effects could play a role in the regioselectivity of the annulation but improved selectivity was not observed in the reaction to give16andiso\u201016 despite the proximalN\u2013Me group. For further discussion see the Supporting Information Section II.D."},{"key":"e_1_2_8_72_1","doi-asserted-by":"publisher","DOI":"10.1021\/cr0783840"},{"key":"e_1_2_8_73_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.joc.3c02870"},{"key":"e_1_2_8_74_1","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.3c02788"},{"key":"e_1_2_8_75_1","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201402093"},{"key":"e_1_2_8_76_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.aec5748"},{"key":"e_1_2_8_77_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja056964d"},{"key":"e_1_2_8_78_1","doi-asserted-by":"publisher","DOI":"10.1039\/D2QO00490A"},{"key":"e_1_2_8_79_1","unstructured":"Attempts to perform this transformation using pre\u2010formed organometallic complexes were unsuccessful and generally led to decomposition reflecting the sensitivity of this reaction to in situ concentrations of the reactive intermediates."},{"key":"e_1_2_8_80_1","unstructured":"Although the half\u2010life of ABO2has not been measured attempts to isolate or observe this intermediate have been unsuccessful suggesting that it is short\u2010lived in solution."},{"key":"e_1_2_8_81_1","unstructured":"The M06\u2010L\/6\u2010311++G(d p)\/SDD\/\/B3LYP\u2010D3(BJ)\/6\u201031G(d)\/LANL2DZ method was utilized as it has previously been used to study transition metal catalyzed reactions of strained intermediates; see ref 81."},{"key":"e_1_2_8_82_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41586\u2010020\u20102701\u20102"},{"key":"e_1_2_8_83_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0010\u20108545(98)00073\u20103"},{"key":"e_1_2_8_84_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.orglett.1c02307"},{"key":"e_1_2_8_85_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja01624a010"},{"key":"e_1_2_8_86_1","unstructured":"The Pd\u2013ethylene complex with a biaryl ligand analogous to that in24was also analyzed computationally and found to have even longer Pd\u2013C bond distances of 2.35 \u00c5; see the Supporting Information Section II.H for further details."}],"container-title":["Angewandte Chemie International Edition"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/anie.3724263","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/anie.3724263","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/anie.3724263","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T09:09:16Z","timestamp":1789376956000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/anie.3724263"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,26]]},"references-count":85,"journal-issue":{"issue":"38","published-print":{"date-parts":[[2026,9,14]]}},"alternative-id":["10.1002\/anie.3724263"],"URL":"https:\/\/doi.org\/10.1002\/anie.3724263","archive":["Portico"],"relation":{},"ISSN":["1433-7851","1521-3773"],"issn-type":[{"value":"1433-7851","type":"print"},{"value":"1521-3773","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,26]]},"assertion":[{"value":"2026-05-05","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-08","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-26","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e3724263"}}