24454-38-4Relevant academic research and scientific papers
Reactions of Sodium Diisopropylamide: Liquid-Phase and Solid-Liquid Phase-Transfer Catalysis by N, N, N′, N″, N″-Pentamethyldiethylenetriamine
Algera, Russell F.,Collum, David B.,Ma, Yun,Woltornist, Ryan A.
supporting information, p. 13370 - 13381 (2021/09/03)
Sodium diisopropylamide (NaDA) in N,N-dimethylethylamine (DMEA) and DMEA-hydrocarbon mixtures with added N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDTA) reacts with alkyl halides, epoxides, hydrazones, arenes, alkenes, and allyl ethers. Comparisons of PMDTA with N,N,N′,N′-tetramethylethylenediamine (TMEDA) accompanied by detailed rate and computational studies reveal the importance of the trifunctionality and κ2-κ3 hemilability. Rate studies show exclusively monomer-based reactions of 2-bromooctane, cyclooctene oxide, and dimethylresorcinol. Catalysis with 10 mol % PMDTA shows up to >30-fold accelerations (kcat > 300) with no evidence of inhibition over 10 turnovers. Solid-liquid phase-transfer catalysis (SLPTC) is explored as a means to optimize the catalysis as well as explore the merits of heterogeneous reaction conditions.
Differential Bridging in the Solvolysis of Epimeric Bicyclic Sulfonates. Norbornanes, Part 17
Grob, Cyril A.,Waldner, Adrian,Zutter, Ulrich
, p. 717 - 729 (2007/10/02)
The solvolysis rates and products of the 2-exo- and 2-endo-norbornyl, bicyclooct-8-yl, bicyclonon-2-yl, bicyclooct-6-yl, bicyclooct-2-yl and bicyclonon-6-yl p-toluenesulfonates 10-15, respectively, are reported.The exo/endo rate ratios for these epimeric secondary tosylates in 80percent EtOH varied from 1125 for 11 to 1.6 for 15.The relative rates varied between 2278 for exo-10 and 4E-3 for endo-11.The hydrolysis products were mainly rearrenged alcohols and olefins.The unrearrenged alcohols from the exo-tosylates were formed with complete or predominant retention of configuration, whereas those derived from the endo-tosylates were mostly inverted.These results confirm the hypothesis that relative rates, as well as products, are largely determined by the degree of bridging between the cationic center and a dorsal C-atom in the transition state and in the resulting ion pairs.Since bridging is a directed bonding interaction, it is subject to the same angle and conformational strains as ordinary covalent bonds.But bridging requires less geometrical change than the formation of normal bonds and of nonclassical ions.
CYCLIC α,β-EPOXYSILANES ACID-CATALYSED REACTIONS OF 1-TRIMETHYLSILYLCYCLOOCTENE OXIDE
Nagendrappa, Gopalpur
, p. 2429 - 2434 (2007/10/02)
The acid-catalysed reactions of medium ring α,β-epoxysilane 1 are described.The epoxide 1 gives exclusively the bicyclic alcohol 2 with boron trifluoride etherate.With aqueous sulphuric acid the products are due to both transannular ring closure, 2, and transannular hydride migration, 3 and 4. trans-Cyclooctene derivatives 3 and 4 are formed by the trans-elimination of trimethylsilanol from the likely intermediate β-hydroxysilanes 10 and 11.The results with methanolic sulphuric acid are similar.It is also noticed that the hydride migration is facilitated by the nucleophilic strength of the medium.
