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Practical stereoselective synthesis of (2,3,4,5‐tetrahydro‐1 H ‐benzo[ b ]azepin‐5‐yl)acetic acid
Author(s) -
Shinohara Tomoichi,
Kondo Kazumi,
Ogawa Hidenori,
Mori Toyoki,
Nozaki Kyoko,
Hiyama Tamejiro
Publication year - 2000
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/(sici)1520-636x(2000)12:5/6<425::aid-chir23>3.0.co;2-e
Subject(s) - chemistry , acetic acid , enantioselective synthesis , stereoselectivity , sulfonyl , toluene , catalysis , yield (engineering) , medicinal chemistry , carboxylic acid , stereochemistry , organic chemistry , alkyl , materials science , metallurgy
Highly enantioselective asymmetric hydrogenation of readily accessible olefins, ( E )‐ and ( Z )‐[1‐(toluene‐4‐sulfonyl)‐1,2,3,4‐tetrahydro‐1 H ‐benzo[ b ]azepin‐5‐ylidene]acetic acid ( 4a and 4b , respectively) and [1‐(toluene‐4‐sulfonyl)‐2,3‐dihydro‐1 H ‐benzo[ b ]azepin‐5‐yl]acetic acid ( 4c ), is presented as an efficient and straightforward route to ( R )‐[1‐(toluene‐4‐sulfonyl)‐2,3,4,5‐tetrahydro‐1 H ‐benzo[ b ]azepin‐5‐yl]acetic acid [( R )‐ 1 ] which is a key intermediate for the synthesis of non‐peptide AVP V 2 ‐agonist. Hydrogenation of carboxylic acid 4c gave ( R )‐ 1 in quantitative yield and 85% ee using Ru(OAc) 2 [( S )‐H 8 ‐BINAP], a Ru(II) complex of a partially hydrogenated BINAP (H 8 ‐BINAP), as a catalyst. When ( R )‐ 1 of 76% ee was transformed into the corresponding isopropylamide 6 , pure enantiomer ( R )‐ 6 was obtained in 75% yield by recrystallization from MeOH. Chirality 12:425–430, 2000. © 2000 Wiley‐Liss, Inc.