Dynamic NMR and X-ray diffraction study of (N-B)-diphenyl(2-aminoethoxy) borane derivatives of ephedrines and pseudoephedrines

Höpfl, Herbert; Farfán, Norberto; Castillo, David Jiménez; Santillán, Rosa; Contreras, Rosalinda; Martínez‐Martínez, Francisco J.; Galván, Marcelo; Alvaréz, R S; Fernández, Lilia; Halut, Sabine; Daran, Jean‐Claude

doi:10.1016/s0022-328x(97)00193-9

Cited by 34 publications

(23 citation statements)

References 34 publications

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“…The bond angle between C 6 -B 2 -C 12 atoms was generally more open (117.9º) because of electronic repulsion between the two phenyl groups that causes the bond angle between O 1 -B 2 -N 3 atoms to be more closed, at 97.9°. The bond angles of C 6 -B 2 -C 12 and O 1 -B 2 -N 3 atoms obtained with B3LYP/6-311++G(d,p) were similar to experimental data presented in the literature by HÖpfl et al [21], at 114.5º and 99.4º, respectively. According to HÖpfl et al [22], the large distances observed for the C-O atoms of these systems are in agreement with covalent interactions between boron and oxygen atoms.…”

Section: Results and Analysissupporting

confidence: 87%

Theoretical Characterization of Three 2,2-Diphenyl-1,3,2-oxazaborolidin-5-ones: Molecules with Fungicide Activities

Vilchis

Velasco

Pénieres

et al. 2009

Molbank

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Section: Results and Analysissupporting

confidence: 87%

Theoretical Characterization of Three 2,2-Diphenyl-1,3,2-oxazaborolidin-5-ones: Molecules with Fungicide Activities

Vilchis

Velasco

Pénieres

et al. 2009

Molbank

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“…The strong intramolecular hydrogen bonds O-H···N of compounds 1-3 15 are indicative that in the corresponding boron or gallium esters, these atoms would occupy the place of the proton, Scheme 2. This idea is supported by the report that diphenyl borinic esters of 4-hydroxypiperidine 7 and 1,4-diethanolpiperazine 24 present strong intramolecular N→B coordination leading to spiro-compounds.…”

Section: -13mentioning

confidence: 72%

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Gálvez-Ruíz¹,

Solano-Ruiz²,

Sánchez-Ruíz³

et al. 2007

Arkivoc

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Compounds 2-(1,3,5-dithiazinan-5-yl)ethanol (1), 2-methyl-2-(1,3,5-dithiazinan-5-yl)ethanol (2) and 2-phenyl-2-(1,3,5-dithiazinan-5-yl)ethanol (3) reacted with BF 3 ⋅OEt 2 and BCl 3 ⋅DMS, 1 and 2 with (Ph 2 B)O, and 2 and 3 with GaCl 3 giving the corresponding chelates, bearing N→BF 2 O, N→BCl 2 O N→BPh 2 O, and N→GaCl 2 O groups. The internal coordination N→M (M = B or Ga) afforded spiro-compounds, where nitrogen is the central atom. Compounds were mainly characterized by 11 B, 1 H and 13 C NMR. The N→B or N→Ga coordination bond was detected in the 1 H spectra because coordination stops the ring inversion of the dithiazinane ring differentiating equatorial and axial protons. The presence of a sterogenic center at the ethanol arm (ligands 2 and 3), differentiates C4H 2 and C6H 2 upon coordination. Minimum energy structures for boron compounds were calculated [ab initio 6-31G(d,p)]. VT NMR experiments for diphenyl borinic esters were performed in order to estimate the N→BPh 2 coordination energy. X-ray diffraction analyses of the hydrochloride of ligand 1 and of the gallium compound prepared from 2 were obtained.

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“…On the other hand, B-NH distances from all three known structures are shorter than the B-N distances for compounds with monosubstituted N in nonconjugated oxazaborolidine rings, which span the range 1.643-1.693 Å (Trujillo et al, 1998;Hopfl et al, 1997Hopfl et al, , 1998Rico et al, 1999). If no substituent is located on the N, typical B-N distances are longer [1.607-1.658 Å; Low et al, 2000;Trujillo et al, 1998;Rettig & Trotter, 1973, 1974, 1976Hopfil et al, 1997;Cynkier & Hope, 1978;Gravelle & Bott, 1995;Cox & Wardell, 2002).…”

Section: Commentmentioning

confidence: 97%

“…If no substituent is located on the N, typical B-N distances are longer [1.607-1.658 Å; Low et al, 2000;Trujillo et al, 1998;Rettig & Trotter, 1973, 1974, 1976Hopfil et al, 1997;Cynkier & Hope, 1978;Gravelle & Bott, 1995;Cox & Wardell, 2002). If two are present, the range is 1.670-1.744 Å (Rettig & Trotter, 1983;Huskens et al, 1998;Hopfl et al, 1997Hopfl et al, , 1998Ebeling et al, 1989;Short & Masamune, 1989).…”

Section: Commentmentioning

confidence: 99%

A 1,3,2-oxazaborolidine dimer derived from (S)-α,α-diphenylprolinol

et al. 2004

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The reaction of (S)‐α,α‐diphenylprolinol with an excess of borane–tetrahydrofuran complex yields a stable crystalline material with the composition C34H38B2N2O2, which features a borane adduct of a spirocyclic structure with two oxazaborolidine rings joined by a central tetrahedral B atom. This dimeric oxazaborolidine complex, viz. 3,3,3′,3′‐tetraphenyl‐1,1′‐spirobi(3a,4,5,6‐tetrahydro‐3H‐pyrrolo[1,2‐c][1,3,2]oxazaborole)–7‐borane, is the dominant product under various reaction conditions; its crystal structure is consistent with 11B, 1H and 13C NMR and IR analyses.

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Dynamic NMR and X-ray diffraction study of (N-B)-diphenyl(2-aminoethoxy) borane derivatives of ephedrines and pseudoephedrines

Cited by 34 publications

References 34 publications

Theoretical Characterization of Three 2,2-Diphenyl-1,3,2-oxazaborolidin-5-ones: Molecules with Fungicide Activities

Theoretical Characterization of Three 2,2-Diphenyl-1,3,2-oxazaborolidin-5-ones: Molecules with Fungicide Activities

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

A 1,3,2-oxazaborolidine dimer derived from (S)-α,α-diphenylprolinol

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