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. 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. 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. 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. XXXVI. 2,2-Dimethyl-3,3-diphenyl-1,4-dioxa-2-azonia-3-boratacyclohexane

1989 ◽  
Vol 67 (12) ◽  
pp. 2218-2221 ◽  
Author(s):  
Klaus Drückler ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Boron Compound ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group

The synthesis of O-(2-hydroxyethyl)-N,N-dimethylhydroxylamine and its reaction with oxybis(diphenylborane) to yield the title compound are reported. Crystals of 2,2-dimethyl-3,3-diphenyl-1,4-dioxa-2-azonia-3-boratacyclohexane are orthorhombic, a = 7.0332(6), b = 9.2269(6), c = 22.967(2) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.051 and Rw = 0.047 for 1247 reflections with 1 ≥ 2σ(I). The molecule exhibits the longest N—B and the shortest O—B distances (1.723(6) and 1.468(5) Å, respectively, corrected for libration) yet reported for a six-membered N,O-chelate of diphenylboron. Keywords: crystal structure, boron compound, organoboron compound.

Structural studies of organoboron compounds. XXXIX.1 1,4-Bis(2,2-diethoxyethyl)-6,8-diphenyl-5,7,9-trioxa-4-aza-1-azonia-8- bora-6-boratabicyclo[4.3.0]nonane

1990 ◽  
Vol 68 (10) ◽  
pp. 1791-1796 ◽  
Author(s):  
Henning Amt ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Reaction of N,N′-1,2-ethanediylidenebis(2,2-diethoxyethanamine)- N,N′-dioxide and phenylboronic acid yields the title compound. Crystals of 1,4-bis(2,2-diethoxyethyl)-6,8-diphenyl-5,7,9-trioxa-4-aza-1-azonia-8-bora-6-boratabicyclo[4.3.0]-nonane are triclinic, a = 12.625(2), b = 13.962(2), c = 9.273(1) Å, α = 104.81(1), β = 98.61(1), γ = 106.52(1)°, 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 = 0.058 and Rw = 0.081 for 3677 reflections with I ≥ 3σ(I). The molecule has a bicyclo[4.3.0]nonane structure containing one transannular N—B bond. Important bond lengths are sp3-bomn, N—B = 1.759(3), O—B = 1.435(3) and 1.454(3), C—B = 1.579(4); sp2-boron, O—B = 1.335(3) and 1.404(3), C—B = 1.557(4) Å. The (sp3)B—C(phenyl) bond is the shortest yet reported for this type of compound.Keywords: crystal structure, boron compound, organoboron 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. LIII. N,N-Diethylhydroxylamine-(O-B)1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5- boratabicyclo[3.3.0]octane

1992 ◽  
Vol 70 (7) ◽  
pp. 2022-2026 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Hydrogen Bond ◽  
Least Squares ◽  
Title Compound ◽  
Condensation Product ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
High Yield ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths

Reaction of the condensation product of N,N′-dimethyl-N,N′-dihydroxymethanediamine and phenylboronic acid with N,N-diethylhydroxylamine gives N,N-diethylhydroxylamine(O-B)1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane [3-(2-ethyl-1-oxa-2-azoniabutyl)-1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3,5-diboratabicyclo[3.3.0]octane, 3] in high yield. Crystals of 3 are orthorhombic, a = 11.8132(11), b = 15.4768(11), c = 11.7325(16) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039 and Rw = 0.044 for 1729 reflections with I ≥ 2σ(I). The title compound is the second example of this recently characterized class of O-B coordinated hydroxylamine complexes, stabilized by an intramolecular [Formula: see text] hydrogen bond [Formula: see text]. Bond lengths about boron are: B—O(N) = 1.482(4)–1.526(4), B—O(B) = 1.412(4) and 1.420(4), B—N = 1.712(4), B—C = 1.591(5) and 1.602(5) Å.

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