An Efficient Synthesis of 4-Aryl-1,2,3,4-Tetrahydroisoquinolines

Isoxazolinoisoquinoline Heterocycles via Solid-Phase Reissert and Suzuki Reactions

“…In our first test of this exo -olefin versus endo -enamide competition in the Reissert series, we felt it was prudent to bias the system toward exo-addition by placing a bulky substituent at the isoquinoline C4-position. Thus, 4-phenylisoquinoline was selected and Reissert formation (® 4 ) followed by LDA-mediated C1-allylation delivered ® 5a . We found that in situ generation of CH 3 CH 2 C⋮N + O - (nitropropane + PhNCO + Et 3 N) resulted in concomitant 1,3-dipolar cycloaddition with complete exo-selectivity based on analysis of the crude hydrolysis product .…”

Alternative Formal Synthesis of the Potent D1 Dopamine Agonist Dihydroxy-2,3,7,11b-tetrahydro-1H- naphth[1,2,3-de]isoquinoline: Dinapsoline

“…The new retrosynthetic route is illustrated in Scheme . In 1994 Miller and Svoboda described the synthesis of a 4-phenyl-1,2,3,4-tetrahydroisoquinoline from 4-bromoisoquinoline based on the Miyaura−Suzuki cross-coupling reaction (more commonly known as the Suzuki cross-coupling reaction) for the preparation of diaryl compounds. , Their report provided the elements for an improved synthesis of dinapsoline, with the challenge being in our case to prepare the necessary boronic acid. This synthesis is illustrated in Scheme .…”

Silica-Supported Polyphosphoric Acid in the Synthesis of 4-Substituted Tetrahydroisoquinoline Derivatives

“…Due to the uniqueness of the structure and potential medicinal properties of the 4-arylisoquinoline derivatives [ 2 , 3 , 4 , 5 ], many synthetic routes for these compounds [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and especially cherylline have been reported. The Amaryllidaceae [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] have been one of the most studied families of plants because of their alkaloids composition. In 1970, Brossi et al [ 1 ] isolated from Crinum powelli an alkaloid with a 4-aryl-1,2,3,4-tetrahydroisoquinoline structure named cherylline.…”