New enantiopure C2 symmetric bis(2-oxazolinyl)cage (Cage-Box) ligands from 4,5-dicyanopyridazine

7,8-Dicyanotetracyclo[7.3.0.02,605,10]dodec-7-ene 3, obtained from 4,5-dicyanopyridazine 1 and cycloocta-1,5-diene 2 through a three-step pericyclic homodomino process, was found to react with optically active β-amino alcohols 4a–d, under zinc chloride catalysis, to afford a new class of enantiopure C2 symmetric bis(oxazolinyl)cage (Cage-Box) ligands 6a–d, along with the corresponding mono(oxazolinyl) derivatives 5a–d.

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7-Cyano-8-[(4S)-4-isopropyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC19H24N2OEe = 100%[α]D25=-80.9 (c 1.0, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

7-Cyano-8-[(4S)-4-methyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC17H20N2OEe = 100%[α]D25=-99.5 (c 0.5, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

7-Cyano-8-[(4R)-4-phenyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC22H22N2OEe = 100%[α]D25=+107.5 (c 0.1, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4R)

7-Cyano-8-[(4S)-4-tert-butyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC20H26N2OEe = 100%[α]D23=-87.7 (c 0.25, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

7,8-Bis[(4S)-4-isopropyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC24H34N2O2Ee = 100%[α]D24=-89.6 (c 1.0, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

7,8-Bis[(4S)-4-methyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC20H26N2O2Ee = 100%[α]D23=-104.3 (c 0.5, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

7,8-Bis[(4R)-4-phenyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC30H30N2O2Ee = 100%[α]D24=+200.3 (c 0.25, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4R)

7,8-Bis[(4S)-4-tert-butyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-eneC26H38N2O2Ee = 100%[α]D25=-76.8 (c 0.5, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)

{7,8-Bis[(4S)-4-isopropyl-2-oxazolin-2-yl]tetracyclo[7.3.0.02,605,10]dodec-7-ene}zinc(II)chlorideC24H34Cl2N2O2ZnEe = 100%[α]D23=+58.2 (c 0.25, CHCl3)Source of chirality: amino alcoholAbsolute configuration: (4S)