127931-16-2Relevant articles and documents
Organocatalytic enantioselective synthesis of β-blockers: (S)-propranolol and (S)-naftopidil
Panchgalle, Sharad P.,Gore, Rohitkumar G.,Chavan, Subhash P.,Kalkote, Uttam R.
, p. 1767 - 1770 (2009)
An efficient enantioselective synthesis of β-adrenergic blockers (S)-propranolol and (S)-naftopidil with >98% ee using an l-proline-catalyzed α-aminoxylation of an aldehyde as a key step is described.
Silver nanoparticle-catalysed phenolysis of epoxides under neutral conditions: Scope and limitations of metal nanoparticles and applications towards drug synthesis
Seth, Kapileswar,Roy, Sudipta Raha,Kommi, Damodara N.,Pipaliya, Bhavin V.,Chakraborti, Asit K.
, p. 164 - 172 (2014/06/23)
Chemo- and regio-selective epoxide phenolysis is reported for the first time under neutral condition catalysed by silver nanoparticles. Other metal nanoparticles (e.g., Au, Pd, Cu, In, and Ru) are less effective. The choice of solvent is critical with 2-propanol being the best followed by DEF. Amongst various stabilisers used (surfactants, PEGs, tetra-alkylammonium halides) the tetra-alkylammonium halides are found to be the most effective (TBAF > TBAB > TBACl > TBAI). The role of the silver nanoparticles is envisaged as synchronous mode epoxide-phenol dual activation via a cooperative network of coordination, anion-π interaction, and hydrogen bond. The silver nanoparticles are recovered and reused for five consecutive times. The reaction has been used for the synthesis of propranolol and naftopidil as a few representative cardiovascular drugs.
Zinc(II) perchlorate hexahydrate catalyzed opening of epoxide ring by amines: Applications to synthesis of (RS)/(R)-propranolols and (RS)/(R)/(S)-naftopidils
Shivani,Pujala, Brahmam,Chakraborti, Asit K.
, p. 3713 - 3722 (2008/02/05)
(Figure Presented) Commercially available zinc(II) Perchlorate hexahydrate [Zn(ClO4)2·6H2O] was found to be a new and highly efficient catalyst for opening of epoxide rings by amines affording 2-amino alcohols in high yields under solvent-free conditions and with excellent chemo-, regio-, and stereoselectivities. For unsymmetrical epoxides, the regioselectivity was influenced by the electronic and steric factors associated with the epoxides and the amines. A complementarity in the regioselectivity was observed during the reaction of styrene oxide with aromatic and aliphatic amines: aromatic amines provided amino alcohols from nucleophilic attack at the benzylic carbon as major products whereas aliphatic amines resulted in formation of the amino alcohols through reaction at the terminal carbon atom of the epoxide ring as the major/sole products. Reaction of aniline with various glycidic ethers gave the amino alcohols by regioselective nucleophilic attack at the terminal carbon atom of the epoxide ring as the only/major product. Zinc(II) Perchlorate hexahydrate was found to be the best catalyst compared to other metal Perchlorates. The counteranion modulated the catalytic property of the various Zn(II) compounds that followed the order Zn(ClO4) 2·6H2O Zn(BF4)2 ～ Zn(OTf)2 ZnI2 > ZnBr2 > ZnCl2 > Zn(OAc)2 > Zn(CO3)2 in parallelism with the acidic strength of the corresponding protic acids (except for TfOH). The applicability of the methodology was demonstrated by the synthesis of cardiovascular drugs propranolol and naftopidil as racemates and optically active enantiomers.
