REAKSI ADISI ASIMETR1K REAGEN TIPE REFORMATSKY PADA SENYAWA NITRON DAN IMIN

• Main Author: Wahyuningrum, Deana
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/1635
• Institution: Institut Teknologi Bandung

The asymmetric addition of Reformatsky-type reagent, which was generated in situ from diethylzinc and iodoacetic ester, to carbonnitogen double bond in nitrones and imine utilizing (R,R)-DIPT as a chiral auxiliary agent showed fairly moderate to high enantioselective products in fairly high chemical yields. The best results of this type of reaction were achieved from the asymmetric add\"ton to nitrone, 6,7- dimethoxy-3,4-dihydroisoquinoline N-oxide (up t a 73% ee) and Nphenyl- a,-(dibenzylcarbamoyl)methanimine N-oxide (21% ee), the stoichiometric asymmetric addition to imine, N-be \'tzylidene-oaminophenol (91% ee) and the catalytic asymmetric addition to Nbenzylidene- o-aminophenol (39% ee) with fairly high ch a ical yields. The use of additive in this type of reaction was found to be crucial in improving the enantioselectivity of reaction, since the best results mentioned were achieved in the presence of iscquinoline N-oxide or pyridine N-oxide (0.5 molar equivalent) as additive in the reaction of 6,7-dimethoxy-3,4-dihydroisoquinoline N-oxide, and 5 M 1120 in THE (0.8 molar equivalent and 0.16 equivalent for stoichiometric and catalytic asymmetric reaction, respxtively) as additive in the reaction of N-benzylidene-oaminophenol.