[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-639354-105":59,"doc-detail-639354-en":129},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":122,"head_meta":124,"extra_data":126,"updated_unix":128},105,"en","reactivity-of-enyne-allenes-generated-via-an-alder-ene-reaction","Reactivity of Enyne-Allenes Generated via an Alder-Ene Reaction","","Reactivity of tandem Alder-ene transformations of 1,3-diynyl propiolate derivatives produces enyne-allene intermediates whose fate depends on the alkyne substituent. Terminal or aryl-substituted alkynes favor a formal 1,7-H shift to form a new enyne-allene, which then undergoes Myers-Saito cycloaromatization followed by a 1,5-H transfer-mediated cyclization to yield highly functionalized benzo-fused six-membered cycles. Preformed enyne-allene intermediates exhibit comparable reactivity profiles, while mechanistic considerations involve diradical and zwitterionic behavior and oxygen trapping effects.",{"@graph":69,"@context":121},[70,84,104],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/reactivity-of-enyne-allenes-generated-via-an-alder-ene-reaction/639354/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":98,"encodingFormat":97,"isAccessibleForFree":99,"interactionStatistic":100},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/reactivity-of-enyne-allenes-generated-via-an-alder-ene-reaction/639354.png","ImageObject",300,407,{"name":92,"@type":93},"WPS_1790064749","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-22",true,{"@type":101,"interactionType":102,"userInteractionCount":4},"InteractionCounter",{"@type":103},"ViewAction",{"@type":105,"mainEntity":106},"FAQPage",[107,113,117],{"name":108,"@type":109,"acceptedAnswer":110},"What determines whether an enyne-allene undergoes a 1,7-H shift or a Diels–Alder reaction?","Question",{"text":111,"@type":112},"The substituent on the alkyne governs the reaction pathway: terminal or aryl-substituted alkynes promote a formal 1,7-H shift, whereas other conditions favor different outcomes such as Diels–Alder behavior.","Answer",{"name":114,"@type":109,"acceptedAnswer":115},"What is the role of Myers-Saito cycloaromatization in the proposed sequence?",{"text":116,"@type":112},"After the enyne-allene is formed (often via a 1,7-H shift), Myers–Saito cycloaromatization converts it into an arene-based 1,4-σ3-diradical intermediate, enabling subsequent steps that lead to the cyclized products.",{"name":118,"@type":109,"acceptedAnswer":119},"How does the solvent affect product distribution in the initial step?",{"text":120,"@type":112},"Switching from toluene to CH3CN markedly changes products: undistilled CH3CN yields aldehyde-containing products via oxygen trapping, while freshly distilled CH3CN provides mainly 2aa and 2ab. DMF and DMSO further alter distributions toward phenol or nucleophile-derived adducts.","https://schema.org",{"og:url":83,"og:type":123,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":125,"canonical":83},"index,follow",{"doc_id":127,"site_id":62},639354,1792703242,{"code":4,"msg":5,"data":130},{"doc_id":127,"user_id":131,"nickname":92,"user_avatar":132,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":133,"file_id":134,"file_url":135,"file_type":136,"file_size":137,"view_count":4,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":24,"language":138,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":139,"faqs":140,"seo_title":141,"seo_description":67,"update_tm":128,"read_time":142},3985747859154,"https://ap-avatar.wpscdn.com/davatar_276721f389ce27ea32af1340a28f341c","Reactivity of Enyne-Allenes Generated via an Alder-Ene Reaction  \nDuy-Viet Vo, Siyuan Su, Rajdip Karmakar, and Daesung Lee*  \nDepartment of Chemistry, University of Illinois Chicago, 845 West Taylor Street, Chicago, IL 60607 (USA)  \nABSTRACT: Tandem transformations of 1,3-diynyl propiolate derivatives are described. The Alder-ene reaction generatesan enyne-allene, which undergoes a formal 1,7-H shift or a Diels-Alder reaction depending on the substituent on the alkyne. Terminal or aryl-substituted alkyne promotes a 1,7-H shift to generate a new enyne-allene, which undergoes a Myers-Saito cycloaromatization followed by a 1,5-H transfer-mediated cyclization to form highly functionalized benzo-fused 6-membered cycles. The reactivity of the preformed enyne-allene show comparable reactivity profiles.  \nThe Myers-Saito cycloaromatization refers to the cyclization of enyne-allene to form an arene-based 1,4-􀁖􀁓 -diradical. 1,2 Certain anticancer natural products such as neocarzinostatin chromophore3 contain a masked warhead functionality for enyne-allene formation as functionality relies on this aromatization process for their biological mode of action. Enyne-allene-containing molecules' anticancer activity and unique structure spurred extensive mechanistic4 and synthetic5,6 studies. In our investigation of the thermal reaction of ester-tethered triyne A in the presence of a nucleophile, we obtained benzannulation product C (Scheme 1) .7 We believe this novel benzannulation occurs via the Alder-ene reaction to form enyneallene8 B followed by a 1,4-addition of nucleophile. However, if the enyne-allene B contains an aryl substituent (R = Ar), nucleophile trapping occurs in the opposite mode to generate an isomeric product D. The different modes of nucleophile trapping to form products C and D suggest that the enyne-allene B with a silyl group undergoes preferential 1,4-addition with a nucleophile, whereas with anaryl substituent, a formal 1,7-H shift9 becomes favorable to form a different enyne-allene E. The Myers-Saito cycloaromatization of E forms F, which can reveal a zwitterionic10 reactivity to give D. A diradical reactivity of F gives aldehyde G after capturing O2 or tricycle I via 1,5-hydrogen transfer to form H followed by a ring-closure. The substituent-dependent change in product distribution prompted us to investigate the Myers-Saito cyclization reactions of enyne-allenes E with and without nucleophiles. The role of the substituent is crucial for the enyneallene B to undergo a formal 1,7-H shift to generate a new enyne-allene F.9 Interestingly, products derived from the Myers-Saito cyclization of B have not been observed.  \nScheme 1. Reactivity of in situ generated enyne-allenes  \nWe commenced our exploration with 1,3-diynyl-2-heptynoate 1a in toluene under reflux (Table 1), which mainly led to the cleavage of the ester providing 2-heptynoic acid as the major product along with uncharacterizable polymeric material (entry 1) . A drastic change in the reaction profile was observed when the solvent was switched to CH3CN. The reaction in undistilled CH3CN generated product 2aa (30%) was isolated along with 2ab (10%) along with aldehyde 2ac (32%) and unreacted enyne-allene 2ad (10%) (entry 2) . The formation of aldehyde 1bb is the consequence of the trapping of the radical intermediate with molecular oxygen11 and 2ad is just a remaining intermediate. On the other hand, in freshly distilled CH3CN, only two  \nTable 1. Solvent effect on the product distribution  \nO  \n~~ ~~Bu conditions  \n1a O      \nProducts  \n48 h  \n\n| entry | solvent | temp (°C) | products / yield |  |  |\n| --- | --- | --- | --- | --- | --- |\n| 1 | PhMe | 110 | O\u003Cbr>~~  ~~Bu 87% |  |  |\n| 2 | MeCN\u003Cbr>(undistilled) | 82 | HOO\u003Cbr>\u003Cbr>O  \u003Cbr>\u003Cbr>2aa , 30%\u003Cbr>\u003Cbr>O\u003Cbr>O\u003Cbr>CHO\u003Cbr>| +\u003Cbr>+ | \u003Cbr>\u003Cbr>\u003Cbr>O\u003Cbr>\u003Cbr>\u003Cbr>O\u003Cbr>\u003Cbr>\u003Cbr>\u003Cbr>\u003Cbr>\u003Cbr>2ab , 10%\u003Cbr>O\u003Cbr>\u003Cbr>O\u003Cbr>•\u003Cbr>\u003Cbr>\u003Cbr>|\n| 3 | MeCN\u003Cbr>(distilled) | 82 | 2ac , 32%\u003Cbr>2aa , 52% | + | 2ad , 10%\u003Cbr>2ab , 13% |\n| 4 ","cbCaifZcfO0C0n8B","https://ap.wps.com/l/cbCaifZcfO0C0n8B","pdf",764489,"English","# ABSTRACT\n# Reactivity and mechanism overview\n## Substituent-dependent trapping and cyclization\n# Experimental solvent effects (Table 1)\n# Substrate scope and product yields (Table 2)","[{\"question\":\"What determines whether an enyne-allene undergoes a 1,7-H shift or a Diels–Alder reaction?\",\"answer\":\"The substituent on the alkyne governs the reaction pathway: terminal or aryl-substituted alkynes promote a formal 1,7-H shift, whereas other conditions favor different outcomes such as Diels–Alder behavior.\"},{\"question\":\"What is the role of Myers-Saito cycloaromatization in the proposed sequence?\",\"answer\":\"After the enyne-allene is formed (often via a 1,7-H shift), Myers–Saito cycloaromatization converts it into an arene-based 1,4-σ3-diradical intermediate, enabling subsequent steps that lead to the cyclized products.\"},{\"question\":\"How does the solvent affect product distribution in the initial step?\",\"answer\":\"Switching from toluene to CH3CN markedly changes products: undistilled CH3CN yields aldehyde-containing products via oxygen trapping, while freshly distilled CH3CN provides mainly 2aa and 2ab. DMF and DMSO further alter distributions toward phenol or nucleophile-derived adducts.\"}]","Reactivity of Enyne-Allenes Generated via an Alder-Ene Reaction | PDF",13]