{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,20]],"date-time":"2026-05-20T16:27:23Z","timestamp":1779294443213,"version":"3.51.4"},"reference-count":53,"publisher":"Wiley","issue":"28","license":[{"start":{"date-parts":[[2023,4,4]],"date-time":"2023-04-04T00:00:00Z","timestamp":1680566400000},"content-version":"am","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2023,4,4]],"date-time":"2023-04-04T00:00:00Z","timestamp":1680566400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["DP180100904"],"award-info":[{"award-number":["DP180100904"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["chemistry-europe.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2023,5,16]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>It is well documented in the literature that 1,6\u2010enynes are cyclized using PhI(OAc)<jats:sub>2<\/jats:sub> (PIDA) in the presence of Pd(OAc)<jats:sub>2<\/jats:sub> as a catalyst to yield cyclopropyl ketones. In contrast, it has been reported that when 1,6\u2010enynes are substituted by a hydroxy group at the \u03b1\u2010position to the alkyne, the chemoselectivity of the cyclization reaction is altered, and polycyclic oxa\u2010heterocycles are formed. This suggests that the hydroxy substituent plays a crucial role in changing the mechanism of the reaction. The aim of this study is to use density functional theory (DFT) calculations at the SMD\/M06\u2010D3\/def2TZVP\/\/SMD\/M06\/SDD,6\u201031G(d) level of theory to shed light on the reason for this change by investigating the detailed mechanistic aspects of these transformations. This study demonstrates that the electronic nature of the Pd catalyst changes from \u03c0\u2010philicity to oxophilicity during the catalytic cycle, and this change plays an essential role in controlling the chemoselectivity of the cyclization reactions. In addition, it was found that (1) the hypervalent iodine reagent PIDA serves not only as an oxidant for the oxidation of Pd(II) to Pd(IV), but also as a nucleophile that drives the acetoxypalladation step of the reaction, (2) the oxidation of Pd(II) to Pd(IV) by the iodonium ion [PhIOAc]<jats:sup>+<\/jats:sup> occurs via an interesting mechanism involving coordination of [PhIOAc]<jats:sup>+<\/jats:sup> to the Pd(II) centre, followed by a twist in the hypervalent iodine, and (3) Pd \u03c0\u2010complexes are not very susceptible to oxidation. (4) A Pd(II) complex can be six coordinate if the Pd centre is partially oxidized.<\/jats:p>","DOI":"10.1002\/chem.202300115","type":"journal-article","created":{"date-parts":[[2023,4,4]],"date-time":"2023-04-04T06:22:58Z","timestamp":1680589378000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Factors Influencing the Chemoselectivity of Pd(OAc)<sub>2<\/sub>\u2010Catalyzed Cyclization Reactions Involving 1,6\u2010Enynes as a Substrate and PhI(OAc)<sub>2<\/sub> as a Reagent"],"prefix":"10.1002","volume":"29","author":[{"given":"Farshad","family":"Shiri","sequence":"first","affiliation":[{"name":"Department of Chemistry Islamic Azad University  Central Tehran Branch, Poonak Tehran 1469669191 Iran"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2383-6380","authenticated-orcid":false,"given":"Alireza","family":"Ariafard","sequence":"additional","affiliation":[{"name":"Department of Chemistry Islamic Azad University  Central Tehran Branch, Poonak Tehran 1469669191 Iran"},{"name":"School of Natural Sciences (Chemistry) University of Tasmania  Private Bag 75 Hobart TAS 7001 Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2023,4,4]]},"reference":[{"key":"e_1_2_8_1_1","unstructured":"\u00a0"},{"key":"e_1_2_8_2_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja0112184"},{"key":"e_1_2_8_3_2","doi-asserted-by":"publisher","DOI":"10.1021\/acs.orglett.0c02310"},{"key":"e_1_2_8_4_2","doi-asserted-by":"publisher","DOI":"10.1039\/C7QO00702G"},{"key":"e_1_2_8_5_2","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200301699"},{"key":"e_1_2_8_6_1","unstructured":"\u00a0"},{"key":"e_1_2_8_7_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00292a065"},{"key":"e_1_2_8_8_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00301a056"},{"key":"e_1_2_8_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)94977-3"},{"key":"e_1_2_8_10_1","unstructured":"\u00a0"},{"key":"e_1_2_8_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja071204j"},{"key":"e_1_2_8_12_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja070919j"},{"key":"e_1_2_8_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tetlet.2008.09.108"},{"key":"e_1_2_8_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2008.10.107"},{"key":"e_1_2_8_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja809965e"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.orglett.9b02096"},{"key":"e_1_2_8_17_1","unstructured":"The replacement of enyne 4 with 4a (an enyne experimentally used as the model substrate Ref.\u2005[8] has a very small effect on the relative energies of the key species and consequently has no impact on the conclusion of this study (for details see Figure\u2005S3)."},{"key":"e_1_2_8_18_1","unstructured":"We also evaluated alternatives for the acetoxylation step in which it is mediated directly by PIDA and found them to be unfavorable with activation barriers exceeding 30\u2005kcal\/mol (Figure\u2005S2)."},{"key":"e_1_2_8_19_1","unstructured":"\u00a0"},{"key":"e_1_2_8_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/acscatal.9b03887"},{"key":"e_1_2_8_21_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja1054274"},{"key":"e_1_2_8_22_2","doi-asserted-by":"publisher","DOI":"10.1039\/C7DT04269H"},{"key":"e_1_2_8_23_2","doi-asserted-by":"publisher","DOI":"10.1021\/acs.organomet.7b00751"},{"key":"e_1_2_8_24_2","doi-asserted-by":"publisher","DOI":"10.1039\/C4SC02591A"},{"key":"e_1_2_8_25_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.202002484"},{"key":"e_1_2_8_26_1","unstructured":"The fact that Pd(II) can be six-coordinate if it is partially oxidised is one of the innovative aspects of this study. We discovered a correlation with R2=0.99 between the percentage contribution of dz2 to the NLMO orbital and the distance between Pd and Oa."},{"key":"e_1_2_8_27_1","unstructured":"\u00a0"},{"key":"e_1_2_8_28_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja054446x"},{"key":"e_1_2_8_29_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs200612s"},{"key":"e_1_2_8_30_1","unstructured":"\u00a0"},{"key":"e_1_2_8_31_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200400584"},{"key":"e_1_2_8_32_2","doi-asserted-by":"publisher","DOI":"10.1039\/C5NJ02697K"},{"key":"e_1_2_8_33_1","doi-asserted-by":"publisher","DOI":"10.1039\/D1SC01230D"},{"key":"e_1_2_8_34_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja01607a027"},{"key":"e_1_2_8_35_1","unstructured":"\u00a0"},{"key":"e_1_2_8_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic102323s"},{"key":"e_1_2_8_37_2","doi-asserted-by":"publisher","DOI":"10.1021\/om1005512"},{"key":"e_1_2_8_38_2","doi-asserted-by":"publisher","DOI":"10.1021\/acs.organomet.1c00058"},{"key":"e_1_2_8_39_2","doi-asserted-by":"publisher","DOI":"10.1039\/C7DT00096K"},{"key":"e_1_2_8_40_1","unstructured":"Gaussian 16 Revision C.01 M.\u2005J. 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