Premium
Multicore Artificial Metalloenzymes Derived from Acylated Proteins as Catalysts for the Enantioselective Dihydroxylation and Epoxidation of Styrene Derivatives
Author(s) -
Leurs Melanie,
Dorn Bjoern,
Wilhelm Sascha,
Manisegaran Magiliny,
Tiller Joerg. C.
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201802185
Subject(s) - dihydroxylation , enantioselective synthesis , styrene , chemistry , catalysis , epoxide , ligand (biochemistry) , bovine serum albumin , acylation , moiety , active site , organic chemistry , combinatorial chemistry , stereochemistry , copolymer , biochemistry , polymer , receptor
Artificial metalloenzymes (AME′s) are an interesting class of selective catalysts, where the chiral environment of proteins is used as chiral ligand for a catalytic metal. Commonly, the active site of an enzyme is modified with a catalytically active metal. Here we present an approach, where the commercial proteins lysozyme (LYS) and bovine serum albumin (BSA) can be converted into highly active and enantioselective AME′s. This is achieved by acylation of the proteins primary amino groups, which affords the metal salts in the core of the protein. A series of differently acylated LYS and BSA were reacted with K 2 OsO 2 (OH) 4 , RuCl 3 , and Ti(OMe) 4 , respectively, and the conjugates were tested for their catalytic activity in dihydroxylation and epoxidation of styrene and its derivatives. The best suited system for dihydroxylation is fully acetylated LYS conjugated with K 2 OsO 2 (OH) 4 , which converts styrene to 1,2‐phenylethanediol with an enantioselectivity of 95 % ee ( S ). BSA fully acylated with hexanoic acid and conjugated with three moles RuCl 3 per mole protein shows the highest ee values for the conversion of styrene to the respective epoxide with enenatioselectivities of over 80 % ee ( R ), a TON of more than 2500 and a yield of up to 78 % within 24 h at 40 °C. LYS has two favored selective binding sites for the metal catalyst and BSA has even three. The AME′s with titanate in the active center invert the enantioselectivity of styrene epoxidation.