Synthesis, characterization, and crystal structures of novel intramolecularly base-stabilized borane derivatives with six- and seven-membered chelate rings.

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.