A Novel Synthesis of Substituted 1-Benzyloctahydroisoquinolines by Acid-Catalyzed Cyclization ofN-[2-(Cyclohex-1-enyl)ethyl]-N-styrylformamides

β-Phenylethylamines and the isoquinoline alkaloids (July 1998 to June 1999)

“…The olefins 128a-128c have been cyclised by Lewis acids to the tetrahydroaporphines 129a-129c. 139 The pharmacological properties and physiological effects of apomorphine [140][141][142][143][144] of actinodaphnine, 131 of N-methylactinodaphnine 131 of bulbocapnine, 145,146 of bracteoline, 147 of cassythicine 131 of cathafiline, 131 of cathaformine, 131 of dehydroglaucine, 147 of 7-acetyldehydroglaucine, 147 of 7-benzoyldehydroglaucine, 147 of 7-formyldehydroglaucine, 147 of 7-formyldehydrothalicsimidine, 130 of 7-hydroxydehydrothalicsimidine, 130 of isoboldine, 147 of ocoteine, 131 and of predicentrine 131 have been studied, and a patent claiming 9-Oethylboldine 130 and its analogues as inhibhitors of metalloproteinases has been published. 148…”

Design, Synthesis and Cytotoxicity Evaluation of Tetrahydro β‐Carboline‐Attached Spiroindolones/ Spiroacenapthylene by Using Lemon Juice as a Green Biocatalyst System.

“…), [9][10][11][12][13][14] lewis acids (BF 3 .Et 2 O, SnCl 4 , MgBr 2 .Et 2 O, TiCl 4 , LiCl, Yb(OTf) 3 , Cu(OTf) 2 , Sc(OTf) 3 , AuCl 3 /AgOTf etc.) [15][16][17][18][19][20][21][22][23] and also several miscellaneous catalysts like silica gel, [24] phosphate buffer, [25] β-cyclodextrin-SO 3 H, [26] CoFe 2 O 4 @SiO 2 -SO 3 H, [27] molecular iodine, [28] Dowex 50W-X4 acidic ion exchange resin, [29] heterogeneous acid H 3 PW 12 O 40 and 9-Borabicyclo[3.3.l]non-9yl(9-BBN) triflate [14] etc. These conventional synthetic processes for different pharmaceuticals and other relevant molecules produce large amount of waste and toxic by-product.…”

“…The catalysts involved were mainly bronsted acids (HCl, H 2 SO 4 , H 3 PO 4 , CH 3 COOH, CF 3 COOH, CF 3 SO 3 H, p-tolunesulfonic acid etc. ), [9][10][11][12][13][14] lewis acids (BF 3 .Et 2 O, SnCl 4 , MgBr 2 .Et 2 O, TiCl 4 , LiCl, Yb(OTf) 3 , Cu(OTf) 2 , Sc(OTf) 3 , AuCl 3 /AgOTf etc.) [15][16][17][18][19][20][21][22][23] and also several miscellaneous catalysts like silica gel, [24] phosphate buffer, [25] β-cyclodextrin-SO 3 H, [26] CoFe 2 O 4 @SiO 2 -SO 3 H, [27] molecular iodine, [28] Dowex 50W-X4 acidic ion exchange resin, [29] heterogeneous acid H 3 PW 12 O 40 and 9-Borabicyclo[3.3.l]non-9yl(9-BBN) triflate [14] etc.…”

Superacid‐Catalyzed Reactions

“…Other Rearrangements and CyclizationsSheldon and co-workers859 have performed the cyclization of N-formyl enamide 249 in triflic acid or over Nafion-H to form the corresponding N-formyloctahydroisoquinolines starting compounds in the synthesis of N-formylmorphinanes [Eq. (5.313)], but activities decreased with repeated use because of the leaching of Nafion resin.…”