{"doi":"10.1021/ja9522241","title":"Structural Effects Affecting the Thermal Electrocyclic Ring Closure of Vinylallenes to Alkylidenecyclobutenes","abstract":null,"journal":"Journal of the American Chemical Society","year":1996,"id":687003,"datarank":0.5333022092234121,"base_score":3.5553480614894135,"endowment":3.5553480614894135,"self_citation_contribution":0.5333022092234121,"citation_network_contribution":0.0,"self_endowment_contribution":0.5333022092234121,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":34,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":685474,"name":"Jesús Rodríguez","orcid":null,"position":1,"is_corresponding":false},{"id":1794758,"name":"José García Rey","orcid":null,"position":2,"is_corresponding":false},{"id":142321,"name":"Angel R. de Lera","orcid":null,"position":3,"is_corresponding":false},{"id":178782,"name":"Susana López","orcid":"0000-0001-6336-9209","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Structural Effects Affecting the Thermal Electrocyclic Ring Closure of Vinylallenes to Alkylidenecyclobutenes","abstract":"The thermal electrocyclic ring closure of (2 E,7 E )-3,4,7-trialkylnona-2,4,5,7-tetraenes (divinyl-4,5-allenes) is regioselective, occurring at the most sterically congested vinylallene subunit to afford the trisubstituted alkylidenecyclobutene. Ring closure of both divinylallenes and vinylallenes displays high torquoselectivity (exclusive formation of the ( E )-alkylidenecyclobutenes) when the substituent at C 4 is a sterically demanding alkyl group and the substituent at C 2 is a formyl group. Ab initio calculations clearly demonstrate the dominant steric influence of the bulky C 4 substituent in these selectivities. However, torquoselectivity appears to be enhanced if cyclization involves loss of conjugation by a π system encompassing the C 2 substituent.","is_dataset_classified":null,"base_score":3.5553480614894135,"endowment":3.5553480614894135,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"26207759","pmcid":null,"openalex_id":"https://openalex.org/W2951800301","authors":[],"funders":[],"total_grants":0,"fwci":2.2573,"citation_percentile":0.87267255,"influential_citations":0,"citation_trend":[{"year":2014,"count":1},{"year":2015,"count":1},{"year":2017,"count":2},{"year":2018,"count":1},{"year":2022,"count":1},{"year":2023,"count":2},{"year":2024,"count":1}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://pubs.acs.org/doi/pdf/10.1021/ja9522241","host_type":"publisher"},{"url":"https://doi.org/10.1021/ja9522241","host_type":"journal"}],"fields_of_study":["Cyclization and Aryne Chemistry","Organic Chemistry Cycloaddition Reactions","Catalytic Alkyne Reactions"],"mesh_terms":[],"keywords":["Substituent","Chemistry","Steric effects","Ring (chemistry)","Regioselectivity","Alkyl","Closure (psychology)","Stereochemistry","Electrocyclic reaction","Ab initio","Organic chemistry","Catalysis"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-18T21:04:08.586119Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}