Macrocyclic Mn(III) salen complexes as recyclable catalyst for oxidative kinetic resolution of secondary alcohols

Content Provider	Semantic Scholar
Author	Bera, Prasanta Kumar Maity, Nabin Ch. Abdi, Sayed Hasan Razi Khan, Noor-Ul Hasan Kureshy, Rukhsana I. Bajaj, Hari C.
Copyright Year	2013
Abstract	Abstract New macrocyclic chiral Mn(III) salen complexes ( C1 – C4 ) were synthesized and were used as catalysts for oxidative kinetic resolution (OKR) of secondary alcohols with diacetoxyiodobenzene (PhI(OAc) 2 ) and N -bromosuccinimide (NBS), in biphasic dichloromethane: water solvent mixture. Good to excellent enantioselectivities were achieved with catalyst C2 for several secondary alcohols having different steric environment. In general with catalyst C2 , NBS as a co-oxidant showed better enantioselectivity than PhI(OAc) 2 in OKR. The catalyst C2 was easily retrieved from the reaction mixture by the addition of hexane and recycled seven times both with NBS and PhI(OAc) 2 as co-oxidants without losing its performance. Based on the experimental results a mechanism for OKR of racemic 1-phenylethanol has been proposed where ( R , R )-Mn-salen preferably binds with ( S )-1-phenylethanol to give ( R )-1-phenylethanol in excess at the end of the reaction.
Starting Page	542
Ending Page	551
Page Count	10
File Format	PDF HTM / HTML
DOI	10.1016/j.apcata.2013.07.055
Volume Number	467
Alternate Webpage(s)	http://shodhganga.inflibnet.ac.in:8080/jspui/bitstream/10603/35843/17/17_awards.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article