title: Asymmetric aminolytic kinetic resolution of racemic epoxides using recyclable chiral polymeric Co(III)-salen complexes: a protocol for total utilization of racemic epoxide in the synthesis of (R)-Naftopidil and (S)-Propranolol.
abstract: Chiral polymeric Co(III) salen complexes with chiral ((R)/(S)-BINOL, diethyl tartrate) and achiral (piperazine and trigol) linkers with varying stereogenic centers were synthesized for the first time and used as catalysts for aminolytic kinetic resolution (AKR) of a variety of terminal epoxides and glycidyl ethers to get enantio-pure epoxides (ee, 99%) and N-protected β-amino alcohols (ee, 99%) with quantitative yield in 16 h at RT under optimized reaction conditions. This protocol was also used for the synthesis of two enantiomerically pure drug molecules (R)-Naftopidil (α1-blocker) and (S)-Propranolol (β-blocker) as a key step via AKR of single racemic naphthylglycidyl ether with Boc-protected isoproylamine with 100% epoxide utilization at 1 g level. The catalyst 1 was successfully recycled for a number of times.
authors.affiliation: Discipline of Inorganic Materials and Catalysis and ‡Academy of Scientific and Innovative Research (AcSIR), Central Salt and Marine Chemicals Research Institute (CSMCRI) , Council of Scientific & Industrial Research (CSIR), G. B. Marg, Bhavnagar- 364 021, Gujarat, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Kumar
authors.forename: Rukhsana I
authors.initials: RI
authors.lastname: Kureshy
authors.forename: Arpan K
authors.initials: AK
authors.lastname: Shah
authors.forename: Anjan
authors.initials: A
authors.lastname: Das
authors.forename: Noor-ul H
authors.initials: NU
authors.lastname: Khan
authors.forename: Sayed H R
authors.initials: SH
authors.lastname: Abdi
authors.forename: Hari C
authors.initials: HC
authors.lastname: Bajaj
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry; D011433:Propranolol / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D004852:Epoxy Compounds; D005029:Ethylenediamines; D009281:Naphthalenes; D009942:Organometallic Compounds; D010879:Piperazines; D003035:Cobalt; C011452:disalicylaldehyde ethylenediamine; D011433:Propranolol; C064357:naftopidil