Benzoylmethylenetriphenylphosphorane, C26H21OP

Kalyanasundari, M.; Panchanatheswaran, Krishnaswamy; Parthasarathi, Viraraghavan; Robinson, Ward T.; Wen, H.

doi:10.1107/s0108270194001137

Cited by 21 publications

(21 citation statements)

References 4 publications

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“…The mean deviation of these atoms from the plane is only 0.0611 Å and the largest deviation from the plane is -0.1046 Å for C19 (H19 lies -0.1285 Å from the defined plane). As suggested by Kalyanasundari et al,28 this planarity also supports the resonance delocalization model. It is reflected again in the torsion angles for this region of the molecule, P1-C19-C20-O1 = 175.35(10) • , P1-C19-C20-O2 = -6.3(2) • , C19-C20-O1-N1 = -10.72 (18) • and O2-C20-O1-N1 = 170.70 (11) • , all values similar to those reported by Spencer et al 29 and Kalyanasundari et al 28 The non-bonded distance between P1 and O2 is 2.94 Å , significantly less than the sum of the van der Waals radii for phosphorus and oxygen (3.3 Å ).…”

Section: Scheme 5 Reaction Of Ph 3 Pcco With Tempo-hsupporting

confidence: 69%

“…As suggested by Kalyanasundari et al,28 this planarity also supports the resonance delocalization model. It is reflected again in the torsion angles for this region of the molecule, P1-C19-C20-O1 = 175.35(10) • , P1-C19-C20-O2 = -6.3(2) • , C19-C20-O1-N1 = -10.72 (18) • and O2-C20-O1-N1 = 170.70 (11) • , all values similar to those reported by Spencer et al 29 and Kalyanasundari et al 28 The non-bonded distance between P1 and O2 is 2.94 Å , significantly less than the sum of the van der Waals radii for phosphorus and oxygen (3.3 Å ). 30 As described by both Spencer et al 29 and Kalyanasundari et al, 26 this suggests that there is a strong intramolecular interaction between the P + and O -charge centres of the enolate resonance contributor, which in turn leads to the molecule adopting a cis orientation.…”

Section: Scheme 5 Reaction Of Ph 3 Pcco With Tempo-hsupporting

confidence: 69%

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Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

et al. 2011

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In this paper, we report a novel synthesis of anhydrous 1-hydroxy-2,2,6,6-tetramethyl-piperidine (TEMPO-H). An X-ray crystal structure and full characterization of the compound are included. Compared to hydrated TEMPO-H, its anhydrous form exhibits improved stability and a differing chemical reactivity. The reactions of anhydrous TEMPO-H with a variety of low-valent carbon centres are described. For example, anhydrous TEMPO-H was reacted with 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), an unsaturated NHC. Crystals of [CHNC 6 H 2 (CH 3 ) 3 ] 2 C ◊ ◊ ◊ HO-(NC 5 H 6 (CH 3 ) 4 ), IMes ◊ ◊ ◊ TEMPO-H, were isolated and a crystal structure determined. The experimental structure is compared to the results of theoretical calculations on the hydrogen-bonded dimer. Anhydrous TEMPO-H was also reacted with the saturated NHC, 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene (SIPr), giving the product [CH 2 Ni-Pr 2 C 6 H 3 ] 2 CH ◊ ◊ ◊ O(NC 5 H 6 (CH 3 ) 4 ). In contrast, the reaction of hydrated TEMPO-H with 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene gave small amounts of the hydrolysis product, N-(2,6-diisopropylphenyl)-N- [2-(2,6-diisopropylphenylamino)ethyl]formamide. Finally, anhydrous TEMPO-H was reacted with (triphenylphosphoranylidene)ketene to generate Ph 3 PC(H)C( O)O(NC 5 H 6 (CH 3 ) 4 ). A full characterization of the product, including an X-ray crystal structure, is described. Scheme 1 Structural isomers formed by the reaction of TEMPO-H (1) with NHCs (2).Access to anhydrous TEMPO-H has not been reported in the literature, but it was clear to us early on that the water in

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Section: Scheme 5 Reaction Of Ph 3 Pcco With Tempo-hsupporting

confidence: 69%

Section: Scheme 5 Reaction Of Ph 3 Pcco With Tempo-hsupporting

confidence: 69%

Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

et al. 2011

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“…The P-C bonds (P1-C8 = 1.759(3), P1-C20 = 1.7736 (17), and P1-C7 = 1.755(11)Å for 2, 5, and 6, respectively) are comparable to analogous distances in [24] and [25] and are longer than the typical double P C bond in methylenetriphenylphosphorane, Ph 3 P CH 2 [26], where there is no opportunity for conjugation with …”

Section: X-ray B3lyp/lanl2dzmentioning

confidence: 93%

Synthesis of new phosphorus ylides: Spectroscopic and X‐ray structural studies

Sabounchei¹,

Shahriary²,

Nojini³

et al. 2010

Heteroatom Chemistry

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“…Thus, the C( (Table 5). 39 On the other hand, the bond length of P(1)-C(19) in the similar elide is 1.706A o 24,27,40 which show that the above bond is considerably elongated to 1.7890 and 1.786(3) A in these complexes ( Table 5). The elongation of the P-C (methine) bond in 1 and 4 relative to the free ylide supports the localization of the positive charge at the phosphorus (Table 5).…”

Section: X-ray Crystallographymentioning

confidence: 96%