- Synthesis and characterization of a cyclotriveratrylene-capped azaphosphatrane
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A cyclotriveratrylene (CTV)-capped azaphosphatrane 4, which contains an endohedral proton within the cavity of the azaphosphatrane, was synthesized in high yield and then characterized. The endohedral proton of 4 was highly sheltered from strongly basic conditions by the CTV-capped structure.
- Makita, Yoshimasa,Furuyoshi, Kenta,Ikeda, Keisuke,Fujita, Tomoyuki,Fujiwara, Shin-Ichi,Ehara, Masahiro,Ogawa, Akiya
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- An Improved Synthesis of the Strong Base P(MeNCH2CH2)3N
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The proazaohosphatrane P(MeNCH2CH2)3N is synthesized in high yield from (HMeNCH2CH2)3N and ClP(NEt2)2.The last compound is synthesized from inexpensive PCl3 and HNEt2. Key Words: strong non-ionic base; proazaphosphatrane; high yield synthesis
- Tang, Jian-sheng,Verkade, John G.
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- The Chloroazaphosphatrane Motif for Halogen Bonding in Solution
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Chloroazaphosphatranes, the corresponding halogenophosphonium cations of the Verkade superbases, were evaluated as a new motif for halogen bonding (XB). Their modulable synthesis allowed for synthetizing chloroazaphosphatranes with various substituents on the nitrogen atoms. The binding constants determined from NMR titration experiments for Cl-, Br-, I-, AcO-, and CN- anions are comparable to those obtained with conventional iodine-based monodentate XB receptors. Remarkably, the protonated azaphosphatrane counterparts display no affinity for anions under the same conditions. The strength of the XB interaction is, to some extent, related to the basicity of the corresponding Verkade superbase. The halogen bonding abilities of this new class of halogen donor motif were also revealed by the Δδ(31P) NMR shift observed in CD2Cl2 solution in the presence of triethylphosphine oxide (TEPO). Thus, chloroazaphosphatranes constitute a new class of halogen bond donors, expanding the repertory of XB motifs mainly based on CAr-I bonds.
- Li, Chunyang,Manick, Anne-Doriane,Yang, Jian,Givaudan, David,Biletskyi, Bohdan,Michaud-Chevalier, Sabine,Dutasta, Jean-Pierre,Hérault, Damien,Bugaut, Xavier,Chatelet, Bastien,Martinez, Alexandre
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supporting information
p. 11964 - 11973
(2021/08/20)
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- Activation of diboron reagents with bronsted bases and alcohols: An experimental and theoretical perspective of the organocatalytic boron conjugate addition reaction
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Bases play an important role in organocatalytic boron conjugate addition reactions. The sole use of MeOH and a base can efficiently transform acyclic and cyclic activated olefins into the corresponding β-borated products in the presence of diboron reagents. Inorganic and organic bases deprotonate MeOH in the presence of diboron reagents. It is concluded, on the basis of theoretical calculations, NMR spectroscopic data, and ESI-MS experiments, that the methoxide anion forms a Lewis acid-base adduct with the diboron reagent. The sp 2 B atom of the methoxide-diboron adduct gains a strongly nucleophilic character, and attacks the electron-deficient olefin. The methanol protonates the intermediate, generating the product and another methoxide anion. This appears to be the simplest method to activate diboron reagents and make them suitable for incorporation into target organic molecules. The simplest method to activate diboron reagents and make them suitable for incorporation in targeted organic molecules seems to be deprotonation of MeOH by base (e.g., Verkade's base) to generate the methoxide anion, which interacts with the diboron reagent to give a nucleophilic Lewis acid-base adduct that promotes the β-boration of α,β-unsaturated carbonyl substrates. Methanol protonates the intermediate to generate the product and another methoxide anion (see scheme). Copyright
- Pubill-Ulldemolins, Cristina,Bonet, Amadeu,Bo, Carles,Gulyas, Henrik,Fernandez, Elena
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supporting information; experimental part
p. 1121 - 1126
(2012/03/22)
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- NOVEL PROPERTIES OF NEW PHOSPHATRANES AND SILATRANES
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The synthesis of the new pro-phosphatranes YP(MeNCH2CH2)3N (Y=lone pair, O, S, Se, BH3 and CH3(1+)) containing four-cordinate phosphorus, and the tbp phosphatranes (Y=H(1+), BrCH2(1+) and Cl(1+)) are reported.New azasilatranes of the type (R=H, Me, SiMe3; Y=H, OMe, OEt) are also reported and the results of nucleophilic substitution studies of the labile hydrogen on the equatorial nitrogens are given.
- Gudat, D.,Lensink, C.,Schmidt, H.,Xi, S.-K.,Verkade, J. G.
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