Isoquinoline-N-Boranes as Precursors to Substituted Tetrahydroisoquinolines
A new approach to the syntheses of 1,2-disubstituted 1,2,3,4-tetrahydroisoquinolines from isoquinoline-N-boranes is described.The method is a "one-pot" operation in which substituents are introduced consecutively as electrophiles and nucleophiles with accompanying reduction of the heterocyclic ring.This procedure differs from the classical ones in that both requisite rings are present in the starting material and thus avoids the inefficient cyclizations of phenethylamine derivatives when unactivated substrates would be required.The synthetic utility of this process is demonstrated with several examples including the alkaloids carnegine and hydrohydrastinine.
Brooks, Donald J.,Dowell, David S.,Minter, David E.,Villarreal, Mark C.
Diprotonative stabilization of ring-opened carbocationic intermediates: conversion of tetrahydroisoquinoline to triarylmethanes
Superacid-promoted conversion of tetrahydroisoquinolines to triarylmethanes via tandem reactions of C-N bond scission, Friedel-Crafts alkylation, C-O bond scission, and electrophilic aromatic amidation was developed. Dication formation was important for stabilizing the ring-opened carbocationic intermediate, which is a new role for diprotonation in reaction mechanisms. This journal is
Kurouchi, Hiroaki
p. 8313 - 8316
(2020/08/17)
Asymmetric synthesis method for preparation of solifenacin
The invention relates to an asymmetric synthesis method for preparation of solifenacin and specifically, discloses a preparation method of solifenacin. The method comprises that ortho-substituted aldehyde as a raw material undergoes a reaction under catalysis of rhodium and a chiral sulfoxide-olefin ligand to produce a key intermediate for high enantioselective addition, and the intermediate is further functionalized and cyclized to form solifenacin. The method is easy to operate, needs mild reaction conditions and has high efficiency and high selectivity.
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(2018/07/10)
PROCESS FOR PREPARING (1S)-1-PHENYL-3,4-DIHYDRO-2(1H)-ISOQUINOLINE-CARBOXYLATE
A process for preparation of (1S)-1-phenyl-3,4-dihydro-2(1H)-isoquinoline-carboxylate (Formula I), comprising reacting (1S)-1-phenyl-3,4-dihydro-2(1H)isoquinoline (Formula II) with carbon dioxide and an alkylating agent R-LG in the presence of a base to obtain the compound of Formula I in an organic solvent. In Formula I and II, R is an alkyl or a substituted alkyl; LG is a leaving group.
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Paragraph 0030
(2015/09/22)
A PROCESS FOR THE PREPARATION OF SOLIFENACIN SALTS AND THEIR INCLUSION INTO PHARMACEUTICAL DOSAGE FORMS
The invention relates to the synthesis of solifenacin, the preparation of its salts and their inclusion into pharmaceutically acceptable dosage forms.
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Page/Page column 32-33
(2010/04/03)
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