Structural studies of organoboron compounds. XLIV. 2,3-Dihydro-3-hydroxy-2,2-tetramethylene-4H-benzoxazin-4-one and its difluoroboron chelate, 2,2-difluoro-4,4-tetramethylene-1,3,5-trioxa-3a-azonia-2-borata-2,3,4,5-tetrahydro- 1H-cyclopenta[a]naphthalene

1991 ◽  
Vol 69 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Boron Trifluoride ◽  
Chelate Ring ◽  
Direct Methods ◽  
Organoboron Compound ◽  
High Yield ◽  
Structural Studies ◽  
Crystal Forms ◽  
Full Matrix ◽  
Weak Binding

The reaction of 2,3-dihydro-3-hydroxy-2,2-tetramethylene-4H-benzoxazin-4-one, 2, and diethyl ether–boron trifluoride yields the difluoroboron chelate 2,2-difluoro-4,4-tetramethylene-1,3,5-trioxa-3a-azonia-2-borata-2,3,4,5-tetrahydro- 1H-cyclo-penta[a]naphthalene, 6, in high yield. There are two crystal forms of 2: 2a, triclinic, [Formula: see text] a = 8.551(1), b = 9.331(3), c = 7.236(1) Å, α = 103.38(2), β = 104.68(1), γ = 80.37(2)°, Z = 2, ρc = 1.35 g cm−3, and 2b, monoclinic, C2/c, a = 17.41(2), b = 10.665(6), c = 12.427(8) Å, β = 115.74(5)°, Z = 8, ρc = 1.40 g cm−3. Crystals of 6 are monoclinic, P21/c, a = 5.354(1), b = 17.654(2), c = 12.844(1) Å, β = 100.11(2)°, Z = 4, ρc = 1.48 g cm−3. The structures were solved by direct methods and were refined by full-matrix least-squares procedures to final R values of 0.046, 0.046, and 0.041 for 1712, 1505, and 1675 reflections with I ≥ 3σ(I), respectively. In both forms of 2, the structures consist of centrosymmetric [Formula: see text] hydrogen-bonded dimers [Formula: see text] for 2a and 2.682(3) Å for 2b). The difluoroboron chelate 6 features a five-membered chelate ring planar within 0.068(2) Å, and bond lengths O—B = 1.504(3) and 1.516(3), F—B = 1.358(3) and 1.359(3) Å indicate weak binding of the ligand to the F2B moiety. Key words: organoboron compound, crystal structure, boron compound

Structural studies of organoboron compounds. XXXVIII. 2,2-Diphenyl-4,4-tetramethylene-1,3,5-trioxa-3a-azonia-2-borata-2,3,4,5-tetrahydro-1H-cyclopenta[a]naphthalene

1990 ◽  
Vol 68 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Good Yield ◽  
Chelate Ring ◽  
Condensation Product ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Weakly Bound ◽  
Full Matrix

Reaction of oxybis(diphenylborane) with the condensation product of salicylohydroxamic acid and cyclopentanone gives the title compound in good yield. Crystals of 2,2-diphenyl-4,4-tetramethylene-1,3,5-trioxa-3a-azonia-2-borata-2,3,4,5-tetrahydro-1H-cyclopenta[a]naphthalene are monoclinic, a = 12.521(1), b = 12.409(1), c = 12.975(1) Å, β = 93.784(8)°, Z = 4, space group P21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.043 and Rw = 0.044 for 1502 reflections with I ≥ 2σ(I). The molecule has a typical diphenylboron hydroxamate structure featuring a five-membered COBON chelate ring. The O,O-chelating ligand is weakly bound to the diphenylboron moiety. Bond lengths (corrected for libration) include: (N)O—B = 1.558(4), (C=)O—B = 1.578(4), and C—B = 1.589(5) and 1.603(5) Å. Keywords: crystal structure, boron compound, organoboron compound.

Structural studies of organoboron compounds. XLVI.1 5,5-Pentamethylene-2-phenyl-4,5-dihydrooxazol-N-oxide(N—O—B)trifluoroborane

1991 ◽  
Vol 69 (8) ◽  
pp. 1212-1216 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ute Schumacher ◽  
Steven J Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Boron Trifluoride ◽  
Organoboron Compound ◽  
High Yield ◽  
Structural Studies ◽  
Open Chain ◽  
Full Matrix ◽  
Boron Complex ◽  
Boron Nitrogen

The reaction of N-hydroxy-N-[(1-hydroxycyclohexyl)methyl]benzamide with dimethylether-boron trifluoride gives 5,5-penta-methylene-2-phenyl-4,5-dihydrooxazol-N-oxide(N—O—B)trifluoroborane [3-(2,2,2-trifluoro-1-oxa-2-borataethyl)-5,5- pentamethylence-2-phenyl-1-oxa-3-azonia-2-cyclopentene] in high yield. Crystals of the product are monoclinic, a = 8.1147(4), b = 15.448(1), c = 11.4144(6) Å, β = 95.133(5)°, Z = 4, space group P21/c. the structure was solved by direct mothods and was refined by full-matrix least-squares procedures to R = 0.043 and Rw = 0.058 for 2178 reflections with I ≥ 3σ(I). the structure analysis confirms that the title compound has an open-chain boron-nitrogen betaine structure and, as such, is the first isolated and fully characterized open-chain non-chelate boron complex of a cycloimidate N-oxide (cyclohydroximate). Bond lengths (corrected for libration) involving the tetrahedrally coordinated boron atom are O—B = 1.530(3) and F—B = 1.370(2)–1.391(2) Å.Key words: crystal structure, organoboron compound, boron compound.

Structural studies of organoboron compounds. XLV. 5,5-Difluoro-2,2-pentamethylene-7,7-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-2,3,4,5,6,7-hexahydroindene

1991 ◽  
Vol 69 (4) ◽  
pp. 681-686 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ute Schumacher ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Key Words ◽  
Boron Trifluoride ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Hydroxamic Acids ◽  
Structural Studies ◽  
Full Matrix ◽  
Regioselective Alkylation

The reaction of N,-dihydroxy-N-(1-hydroxycyclohexyl)methyl-2,2-diphenylacetamide with dimethyl ether-boron trifluoride gives 5,5-difluoro-2,2-pentamethylene-7,7-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-2,3,4,5,6,7-hexahydroindene in nearly quantitative yield. Crystals of the product are triclinic, a = 9.4555(5), b = 9.9813(6), c = 10.5139(9) Å, α = 72.654(7), β = 77.140(5), γ = 88.542(6)°, Z = 2, space group [Formula: see text] The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.044 and Rw = 0.060 for 2971 reflections with I ≥ 3σ(I). The molecule has a six-membered difluoroboron chelate structure, confirming that the regioselective alkylation of N-substituted hydroxamic acids under non-basic conditions leads to imidate N-oxides in cases where intramolecular alkylation occurs. Bond lengths (corrected for libration): (N)O—B = 1.530(3), (C)O—B = 1.451(2), F—B = 1.389(3) and 1.379(3) Å indicate relatively strong binding of the BF2+moiety by the O,O-chelating ligand. Key words: organoboron compound, crystal structure, boron compound.

Structural studies of organoboron compounds. XLI. (3-Hydroxy-2-methyl-1-(p-tolyl)-4-pyridinonato)diphenylboron

1990 ◽  
Vol 68 (10) ◽  
pp. 1803-1807 ◽  
Author(s):  
Chris Orvig ◽  
Steven J. Rettig ◽  
James Trotter ◽  
Zaihui Zhang
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Organoboron Compound ◽  
High Yield ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths ◽  
The Mean ◽  
Independent Molecules

(3-Hydroxy-2-methyl-1-(p-tolyl)-4-pyridinonato)diphenylboron has been prepared in high yield by the reaction of 3-hydroxy-2-methyl-1-(p-tolyl)-4-pyridinone with diphenylborinic acid. Crystals of the hemi-acetone solvate are triclinic, a = 15.119(2), b = 16.528(1), c = 9.5802(9) Å, α = 98.721(6), β = 93.344(8), γ = 102.443(6)°, Z = 4, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.050 and Rw = 0.065 for 4330 reflections with I ≥ 3σ(I). The five-membered chelate rings in both of the two crystallographically independent molecules have flattened B-envelope conformations (maximum deviations from the mean planes = 0.114(4) and 0.065(5) Å). Mean bond lengths O—B = 1.553 and C—B = 1.599 Å are consistent with intermediate strength binding of the diphenylboron moiety by the O,O-chelating ligand. Keywords: crystal structure, organoboron compound.

Structural studies of organoboron compounds. XLIII. 4-[(1-Hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene

1991 ◽  
Vol 69 (3) ◽  
pp. 545-549 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ute Schumacher ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Key Words ◽  
Hydroxamic Acid ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths ◽  
Acid Chelate

The reaction of N′-hydroxy-N-[(1-hydroxycyclohexyl)methyl]benzamide and diphenylborinic anhydride gives 4-[(1-hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene in nearly quantitative yield. Crystals of the product are monoclinic, a = 9.9117(6), b = 13.308(1), c = 17.339(2) Ǻ, β = 99.420(7)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.047 for 2423 reflections with I > 3σ(I). The molecule has a normal five-membered hydroxamic acid chelate structure, the BONCO ring having a B-envelope conformation. Bond lengths (corrected for libration) (N)O—B = 1.535(3), (C)O—B = 1.569(3), C—B = 1.603(3) and 1.601(3) Ǻ are normal for this type of complex. Key words: organoboron compound, boron compound, crystal structure.

Structural studies of organoboron compounds. XLII. 4,6-Bis(1-cyano-1-methylethyl)-2-mesityl-1,3-dioxa-4,6-diaza-2-boracyclohexane

1991 ◽  
Vol 69 (2) ◽  
pp. 234-238 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Least Squares ◽  
Key Words ◽  
Good Yield ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths

The condensation of N,N′-bis(1-cyano-1-methylethyl)-N,N′-dihydroxymethanediamine and mesitylboronic acid gives 4,6-bis(1-cyano-1-methylethyl)-2-mesityl-1,3-dioxa-4,6-diaza-2-boracyclohexane in good yield. Crystals of the latter compound are orthorhombic, a = 15.825(1), b = 17.958(1), c = 14.014(1) Ǻ, Z = 8, space group Pbca. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.037 and Rw = 0.051 for 2844 reflections with 1 ≥ 3σ(I). The molecule has a six-membered cycloboronate structure featuring the first structurally characterized BONCNO ring. The ring was found to have a C-envelope conformation in the solid state. Bond lengths include: O—B(sp2) = 1.356(2) and 1.370(2), and C(aryl)—B = 1.560(2) Ǻ. Key words: organoboron compound, boron compound, crystal structure.

Structural studies of organoboron compounds. XXXV. 4,8-Diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia- 2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene

1989 ◽  
Vol 67 (10) ◽  
pp. 1644-1649 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Boron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Binding Strength ◽  
The Mean

The reaction of Ν,Ν′-diethyloxalohydroxamic acid with oxybis(diphenylborane) yields the title compound. Crystals of 4,8-diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia-2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene are monoclinic, a = 14.3405(9), b = 14.3053(5), c = 14.9301(8) Å, β = 116.136(4)°, Z = 4, space groupP21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.038 and Rw = 0.038 for 3501 reflections with I ≥ 3σ(I). The molecule has a novel bis-six-membered binuclear chelate structure, the Ph2B moieties each being coordinated by (N)O and (C=)O oxygen atoms from different hydroxamate groups. The mean libration-corrected bond distances (C=)O—B, 1.587 Å, (N)O—B, 1.511 Å, and B—C, 1.602 Å, represent the weakest overall binding strength of an O,O-chelating ligand with respect to the Ph2B moiety yet observed for a six-membered O—B—O chelate. Keywords: crystal structure, boron compound, organoboron compound.

Structural studies of organoboron compounds. XXV. Synthesis and structure of (maltolato)diphenylboron

1987 ◽  
Vol 65 (3) ◽  
pp. 590-594 ◽  
Author(s):  
Chris Orvig ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Title Compound ◽  
Spectroscopic Data ◽  
Direct Methods ◽  
High Yield ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Envelope Conformation ◽  
Weak Binding

The reaction of maltol (3-hydroxy-2-methyl-4-pyrone) with diphenylborinic acid affords a high yield of the title compound. Crystals of (maltolato)diphenylboron are monoclinic, a = 14.3481(6), b = 8.3994(3), c = 12.6657(5) Å, β = 100.892(4)°, Z = 4, space group P21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.041 and Rw = 0.052 for 2052 reflections with I ≥ 3σ(1). The molecule contains a five-membered C2O2B ring having a flattened B-envelope conformation, the B atom being displaced 0.081(2) Å from the C2O2 plane. Structural and spectroscopic data are consistent with weak binding of the maltolate oxygen atoms to boron. Bond distances (corrected for libration) are O—B = 1.533(2) and 1.600(3), B—C = 1.600(3) and 1.605(3) Å.

Structural studies of organoboron compounds XLVIII. 1,4-Diphenyl-3,3:6,6-bis(tetramethylene)-2,5,7-trioxa-3,6-diazonia-1,4-diboratabicyclo[2.2.1]heptane

1991 ◽  
Vol 69 (8) ◽  
pp. 1222-1226 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ulf Riebe ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Ring System ◽  
Structural Studies ◽  
Full Matrix ◽  
Moderate Yield ◽  
Atom Bond ◽  
Axis Passing

The reaction of N-hydroxypyrrolidine with either oxybis(diphenylborane) or phenylboronic acid gives 1,4-diphenyl-3,3:6,6-bis(tetramethylene)-2,5,7-trioxa-3,6-diazonia-1,4-diboratabicyclo[2.2.1]heptane in moderate yield. Crystals of the product are orthorhombic, a = 10.984(2), b = 14.619(2), c = 12.311(2) Å, Z = 4, space group Pccn. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039 and Rw = 0.043 for 908 reflections with I ≥ 3σ(I). This is the first heterocyclic [2.2.1]heptane system containing a six-membered BONBON ring and a B—O—B bridge to be structurally characterized. The molecule has exact C2 symmetry with the twofold axis passing through the bridging oxygen atom. Bond lengths involving the tetrahedrally coordinated boron atom are B—O(B) = 1.423(3), B—O(N) = 1.497(3), B—N = 1.703(3), and B—C(phenyl) = 1.577(4) Å. Key words: 2,5,7-trioxa-3,6-diazonia-1,4-diboratabicyclo[2.2.1]heptane ring system, crystal structure, organoboron compound.

Structural studies of organoboron compounds XL. 4,7-Dicyclohexyl-2,2,5,6-tetraphenyl- 1,3-dioxa-4-aza-7-azonia-2-boratacycloheptane

1990 ◽  
Vol 68 (10) ◽  
pp. 1797-1802 ◽  
Author(s):  
Henning Amt ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Least Squares ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Chair Conformation ◽  
Membered Ring ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths

The synthesis of 4,7-dicyclohexyl-2,2,5,6-tetraphenyl-1,3-dioxa-4-aza-7-azonia-2-boratacycloheptane is reported. Crystals of the compound are orthorhombic, a = 10.893(1), b = 28.072(1), c = 10.596(1) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.036 and Rw = 0.043 for 2480 reflections with I ≥ 3σ(I). The molecule has a seven-membered chelate structure. The seven-membered ring, which has a twisted chair conformation, is stabilized by an intramolecular [Formula: see text] hydrogen bond. Bond lengths O—B = 1.468(4) and 1.554(4), C—B = 1.621(5) and 1.626(4) Å are consistent with moderately strong binding of the diphenylboron moiety by the O,O-chelating ligand. Keywords: crystal structure, organoboron compound, boron compound.

Sign in / Sign up

Export Citation Format

Share Document