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Enantioselective Hydrosilylation and Hydrogenation of Alkaloid Precursors
Author(s) -
Brunner Henri,
Kürzinger Alfred,
Mahboobi Siavosh,
Wiegrebe Wolfgang
Publication year - 1988
Publication title -
archiv der pharmazie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 61
eISSN - 1521-4184
pISSN - 0365-6233
DOI - 10.1002/ardp.19883210206
Subject(s) - enantioselective synthesis , chemistry , trifluoroacetic anhydride , hydrosilylation , acetic anhydride , silylation , catalysis , yield (engineering) , organic chemistry , alkaloid , trifluoroacetic acid , oxazoline , medicinal chemistry , materials science , metallurgy
Enantioselective hydrosilylations of the 3,4‐dihydropyrrole derivatives 1a – c and 5 with in‐situ catalysts consisting of [Rh(cod)Cl] 2 and optically active phosphines yield the N ‐silyl compounds 2a – c and 6 in up to 66.1% ee. The N ‐silyl derivatives were treated with acetic formic anhydride or trifluoroacetic anhydride to give the N ‐formyl and N ‐trifluoroacetyl compounds 3a–c, 4a–c, 7 , and 8 . The alkaloids nicotine and macrostomine were synthesized with 63.3 and 33% ee by reduction of the N ‐formyl compounds 8 and 12 . Enantioselective hydrogenations of the N ‐formyl and N ‐trifluoroacetyl‐2‐phenylpyrrolines 14 and 15 with the same in‐situ catalysts produce the cyclic amides 3a and 4a in up to 36.1% ee.