Synthesis, Characterization, and Crystal Structures of Novel Intramolecularly Base-Stabilized Borane Derivatives with Six- and Seven-Membered Chelate Rings

Abstract

The reaction of (2-dimethylaminophenyl)alcohols 1-HOX-2-NMe(2)C(6)H(4) [X = CPh(2) (1), X = CCy(2) (2), X = CPh(2)CH(2) (4)] and 1-phenylaminoalkyl-2-dimethylaminobenzene 1-HN(Ph)X-2-NMe(2)C(6)H(4) [X = C(H)Ph (3), C(H)PhCH(2) (5)] with BH(3)(THF) yielded the BH(2) derivatives 1-H(2)BOX-2-NMe(2)C(6)H(4) [X = CPh(2) (6), CCy(2) (7), CPh(2)CH(2) (9)] and 1-H(2)BN(Ph)X-2-NMe(2)C(6)H(4) [X = C(H)Ph (8), C(H)PhCH(2) (10)]. Treatment of 1-H(2)BOCPh(2)-2-NMe(2)C(6)H(4) (6) with acetic acid gave 1-(CH(3)COO)HBOCPh(2)-2-NMe(2)C(6)H(4) (11). Compounds 6-11 were characterized spectroscopically (NMR, IR, MS). Crystal structure determinations were carried out on 6-11, which are novel examples of structurally characterized BH(2) derivatives containing six- or seven-membered chelate rings. For the chiral compounds 8, 10, and 11, both enantiomers are present in the unit cell.

{μ-[2-(Dimethylamino)phenyl](2-fluorophenyl)methanolato}pentamethyldialuminum(III)

“…For the synthesis of the ligand, see: Al-Masri et al (2004a). For a discussion of chirality in the ligand, see: Al-Masri et al (2004b).…”

“…The pure product was obtained by recrystallization from methanol as a white solid (13.9 g, 82%). The absolute configuration of the ligand could not be determined (Al-Masri et al, 2004b). AlMe 3 (4.0 ml, 1.0 M in toluene, 4.0 mmol) was added to a solution of (2-dimethylamino-phenyl)-(2-fluoro-phenyl)-methanol (0.49 g, 2.0 mmol) in toluene (20 ml) at -10 °C with stirring.…”

Synthesis and characterization of novel intramolecularly base-stabilized BEt2 and BEt derivatives: molecular structures of 1-Et2BOCPh2-2-NMe2C6H4, 1-(CH3COO)EtBOCCy2-2-NMe2C6H4 and BEt(1-OCPh2CH2-2-NMe2C6H4)2

“…In the tricoordinate borane compound 9-phenyl-9-BBN (9-BBN = 9-borabicyclo[3.3.1]nonyl), the signal is observed at 80.4 ppm [13]. The corresponding tetracoordinate BH 2 [d = À2.5 to 4.4 ppm] [2] and BX 2 [X = Cl (d = 7.9À8.6 ppm), X = F (1.3-1.9 ppm)] [1] derivatives of 1-3 exhibit chemical shifts in the same range as the tetracoordinate species in 4-7.…”

“…Boron reagents with reactive boron-substituent bonds [1][2][3][4] are of interest as starting materials for the preparation of transition metal-boron complexes, in medicinal chemistry, catalysis, and hydroboration reactions and as precursors for polymers [5,6]. We recently described the (2-dimethylaminophenyl)alcohols 1-HOX-2-NMe 2 C 6 H 4 [X = CPh 2 (1), X = CCy 2 (2), X = CPh 2 CH 2 (3)] [7], which are suitable for the formation of intramolecularly base-stabilized transition metal [8] and main group compounds [1,2,9] with six-and sevenmembered chelate rings.…”

“…We recently described the (2-dimethylaminophenyl)alcohols 1-HOX-2-NMe 2 C 6 H 4 [X = CPh 2 (1), X = CCy 2 (2), X = CPh 2 CH 2 (3)] [7], which are suitable for the formation of intramolecularly base-stabilized transition metal [8] and main group compounds [1,2,9] with six-and sevenmembered chelate rings.…”