{"doi":"10.1021/acs.joc.2c02841","title":"Mechanism of Pd/Senphos-Catalyzed <i>trans</i> -Hydroboration of 1,3-Enynes: Experimental and Computational Evidence in Support of the Unusual Outer-Sphere Oxidative Addition Pathway","abstract":"The reaction mechanism of the Pd/Senphos-catalyzed trans -hydroboration reaction of 1,3-enynes was investigated using various experimental techniques, including deuterium and double crossover labeling experiments, X-ray crystallographic characterization of model reaction intermediates, and reaction progress kinetic analysis. Our experimental data are in support of an unusual outer-sphere oxidative addition mechanism where the catecholborane serves as a suitable electrophile to activate the Pd 0 -bound 1,3-enyne substrate to form a Pd-η 3 -π-allyl species, which has been determined to be the likely resting state of the catalytic cycle. Double crossover labeling of the catecholborane points toward a second role played by the borane as a hydride delivery shuttle. Density functional theory calculations reveal that the rate-limiting transition state of the reaction is the hydride abstraction by the catecholborane shuttle, which is consistent with the experimentally determined rate law: rate = k [enyne] 0 [borane] 1 [catalyst] 1 . The computed activation free energy Δ G ‡ = 17.7 kcal/mol and KIE ( k H / k D = 1.3) are also in line with experimental observations. Overall, this work experimentally establishes Lewis acids such as catecholborane as viable electrophilic activators to engage in an outer-sphere oxidative addition reaction and points toward this underutilized mechanism as a general approach to activate unsaturated substrates.","journal":"The Journal of Organic Chemistry","year":2023,"id":339289,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":16,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9452,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":694783,"name":"Ziyong Wang","orcid":"0000-0002-6585-8951","position":1,"is_corresponding":false},{"id":694785,"name":"Walid Lamine","orcid":"0000-0003-1120-3287","position":2,"is_corresponding":false},{"id":993522,"name":"Senmiao Xu","orcid":"0000-0003-0249-8765","position":3,"is_corresponding":false},{"id":694786,"name":"Bo Li","orcid":"0000-0002-2934-4064","position":4,"is_corresponding":false},{"id":694788,"name":"Anna Chrostowska","orcid":"0000-0003-0371-4546","position":5,"is_corresponding":false},{"id":694789,"name":"Karinne Miqueu","orcid":"0000-0002-5960-1877","position":6,"is_corresponding":false},{"id":694790,"name":"Shih‐Yuan Liu","orcid":"0000-0003-3148-9147","position":7,"is_corresponding":false},{"id":993521,"name":"Yuanzhe Zhang","orcid":"0000-0003-2292-8988","position":0,"is_corresponding":true}],"reference_count":69,"raw_metadata":null,"created_at":"2026-07-19T01:10:45.048445Z","pmid":"36752741","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":[]}