{"title":"调节膦酰胺的电子结构以绕过膦进行催化阿贝尔反应","authors":"Nidhi Kumari, Anjana Jagadeesh, Prashant Galav, Avinava Kundu, Biswarup Chakraborty","doi":"10.1021/acs.joc.4c02006","DOIUrl":null,"url":null,"abstract":"A set of structurally analogous, albeit electronically distinct, phosphamides (<b>1aa-10aa</b>) is prepared, and the effect of the electronic amendment due to p-substitution has been tested for the conversion of alcohols to halides via the Appel reaction. The −OMe-substituted diphosphamide (<b>8aa</b>) remains the most active, providing ∼96% conversion of alcohols to halides with a TON of 11 in moderate reaction conditions with a large substrate scope. Halide formation follows a pseudo-first-order rate with a constant rate (<i>k</i><sub>obs</sub>) of 7.13 × 10<sup>–5</sup> s<sup>–1</sup>. Temp-dependent kinetics and Eyring analyses reveal the activation parameters Δ<i>H</i><sup>‡</sup> of 28.95 (±1.6) kcal mol<sup>–1</sup>, Δ<i>S</i><sup>‡</sup> of −70.02 (±0.4) cal K<sup>–1</sup> mol<sup>–1</sup>, and Δ<i>G</i><sup>‡</sup><sub>298</sub> of 49.81 (±1.2) kcal mol<sup>–1</sup>. The deuterium labeling study highlights the O–H dissociation of the alcohol as the rate-determining step, while the Hammett analysis with <i>p</i>-substituted benzyl alcohols indicates a positive charge accumulation at the phosphorus center during the Appel reaction. The HOMO–LUMO energy and NPA analyses show that <i>p</i>–OMe substitutions in <b>8aa</b> make the “P═O” bond more ionic and corresponding aminophosphine is nucleophilic, which are favorable for the Appel reaction. In situ detection of the Appel salt, [R<sub>3</sub>PX]CX<sub>3</sub> and alkoxy phosphonium cation [R<sub>3</sub>POR]X, validates the reaction pathway mediated by the phosphamides.","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Moderation of the Electronic Structure of Phosphamides to Execute the Catalytic Appel Reaction Bypassing Phosphine\",\"authors\":\"Nidhi Kumari, Anjana Jagadeesh, Prashant Galav, Avinava Kundu, Biswarup Chakraborty\",\"doi\":\"10.1021/acs.joc.4c02006\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"A set of structurally analogous, albeit electronically distinct, phosphamides (<b>1aa-10aa</b>) is prepared, and the effect of the electronic amendment due to p-substitution has been tested for the conversion of alcohols to halides via the Appel reaction. The −OMe-substituted diphosphamide (<b>8aa</b>) remains the most active, providing ∼96% conversion of alcohols to halides with a TON of 11 in moderate reaction conditions with a large substrate scope. Halide formation follows a pseudo-first-order rate with a constant rate (<i>k</i><sub>obs</sub>) of 7.13 × 10<sup>–5</sup> s<sup>–1</sup>. Temp-dependent kinetics and Eyring analyses reveal the activation parameters Δ<i>H</i><sup>‡</sup> of 28.95 (±1.6) kcal mol<sup>–1</sup>, Δ<i>S</i><sup>‡</sup> of −70.02 (±0.4) cal K<sup>–1</sup> mol<sup>–1</sup>, and Δ<i>G</i><sup>‡</sup><sub>298</sub> of 49.81 (±1.2) kcal mol<sup>–1</sup>. The deuterium labeling study highlights the O–H dissociation of the alcohol as the rate-determining step, while the Hammett analysis with <i>p</i>-substituted benzyl alcohols indicates a positive charge accumulation at the phosphorus center during the Appel reaction. The HOMO–LUMO energy and NPA analyses show that <i>p</i>–OMe substitutions in <b>8aa</b> make the “P═O” bond more ionic and corresponding aminophosphine is nucleophilic, which are favorable for the Appel reaction. In situ detection of the Appel salt, [R<sub>3</sub>PX]CX<sub>3</sub> and alkoxy phosphonium cation [R<sub>3</sub>POR]X, validates the reaction pathway mediated by the phosphamides.\",\"PeriodicalId\":57,\"journal\":{\"name\":\"The Journal of Organic Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-10-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Journal of Organic Chemistry\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://doi.org/10.1021/acs.joc.4c02006\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, ORGANIC\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Organic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.joc.4c02006","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
Moderation of the Electronic Structure of Phosphamides to Execute the Catalytic Appel Reaction Bypassing Phosphine
A set of structurally analogous, albeit electronically distinct, phosphamides (1aa-10aa) is prepared, and the effect of the electronic amendment due to p-substitution has been tested for the conversion of alcohols to halides via the Appel reaction. The −OMe-substituted diphosphamide (8aa) remains the most active, providing ∼96% conversion of alcohols to halides with a TON of 11 in moderate reaction conditions with a large substrate scope. Halide formation follows a pseudo-first-order rate with a constant rate (kobs) of 7.13 × 10–5 s–1. Temp-dependent kinetics and Eyring analyses reveal the activation parameters ΔH‡ of 28.95 (±1.6) kcal mol–1, ΔS‡ of −70.02 (±0.4) cal K–1 mol–1, and ΔG‡298 of 49.81 (±1.2) kcal mol–1. The deuterium labeling study highlights the O–H dissociation of the alcohol as the rate-determining step, while the Hammett analysis with p-substituted benzyl alcohols indicates a positive charge accumulation at the phosphorus center during the Appel reaction. The HOMO–LUMO energy and NPA analyses show that p–OMe substitutions in 8aa make the “P═O” bond more ionic and corresponding aminophosphine is nucleophilic, which are favorable for the Appel reaction. In situ detection of the Appel salt, [R3PX]CX3 and alkoxy phosphonium cation [R3POR]X, validates the reaction pathway mediated by the phosphamides.
期刊介绍:
The Journal of Organic Chemistry welcomes original contributions of fundamental research in all branches of the theory and practice of organic chemistry. In selecting manuscripts for publication, the editors place emphasis on the quality and novelty of the work, as well as the breadth of interest to the organic chemistry community.