433219-34-2Relevant academic research and scientific papers
Novel syntheses of enantiopure hexahydroimidazo[1,5-b]isoquinolines and tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones via iminium cation cyclizations
Katritzky, Alan R.,Suzuki, Kazuyuki,He, Hai-Ying
, p. 8224 - 8229 (2007/10/03)
Condensations of chiral diamines 11a-c with benzotriazole and formaldehyde gave benzotriazolyl intermediates 12a-c; similar condensations of α-amino-amides 10a-c with benzotriazole and paraformaldehyde gave 14a-c. Subsequent treatment of 12a-c and 14a-c with AlCl3 led to enantiopure tricyclic 1,2,3,5,10,10a-hexahydroimidazo[1,5-b]isoquinolines 1a-c and 2,3,10,10a-tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones 15a-c, respectively, via Lewis acid promoted iminium cation cyclizations.
Convenient syntheses of unsymmetrical imidazolidines
Katritzky, Alan R.,Suzuki, Kazuyuki,He, Hai-Ying
, p. 3109 - 3114 (2007/10/03)
Unsymmetrical imidazolidines 10-14, optically active imidazolidines 20-22, and 2,3-dihydro-1H benzimidazoles 28 and 29 were synthesized in good to excellent yields by Mannich reactions of 1,2-ethanediamines 8a-c, 18a-c, or N-methyl-1,2-benzenediamine (26a) with benzotriazole and formaldehyde, followed by the nucleophilic substitution of the benzotriazolyl group with C- nucleophiles (Grignard reagents, sodium cyanide), an S-nucleophile (benzenethiol), and a P-nucleophile (triethyl phosphite).
Stereoselective syntheses of chiral (3S,9bS)-1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-ones
Katritzky, Alan R.,He, Hai-Ying,Verma, Akhilesh K.
, p. 933 - 938 (2007/10/03)
Chiral (3S,9bS)-1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-ones 11a-11f, 14b,14c and 17a,b were prepared in 78-93% yields with high stereoselectivities (d.e. >99%) by the intermolecular condensations of 2-formylbenzoic acids 10 or 13 or 2-acetylbenzoic acid 15 with chiral diamines 9a-9f and 9h. Compounds 9a-9f and 9h were readily prepared in three steps from optically active N-Boc-α-amino acids 5a-5d.
