Indium–bipyridine-catalyzed, enantioselective thiolysis of meso-epoxides

Abstract

The indium-bipyridine-catalyzed, enantioselective ring-opening of meso-epoxides with aliphatic and aromatic thiols furnished 1,2-mercapto alcohols in good yields and excellent enantioselectivities; the crystal structure of the chiral catalyst reveals a pentagonal-bipyramidal coordination geometry around the indium center.

Synthesis and Application of the Transition Metal Complexes of α-Pyridinyl Alcohols, α-Bipyridinyl Alcohols, α,α’-Pyridinyl Diols and α,α’-Bipyridinyl Diols in Homogeneous Catalysis

“…Formaldehyde reacted to the enolates that possess α -substituent from the same face regardless of the substituents at α -potion. The X-ray crystal structure of the ScBr 3 -( S , S )- 148 revealed a pentagonal bipyramidal structure in which the hydroxy groups of the bipyridinyl diol coordinate to Sc 3+ in a tetradentate manner, which is in agreement with Nakamura et al’s [ 115 ] [InBr 2 - 148 ·H 2 O] + crystal structure 152 . This structure is perhaps a key for the high enantioselectivity.…”

“…A combined Lewis acid-Brønsted acid acidity of the indium(III)-bipyridinyl diol complex was proposed by Nandakumar et al [ 115 ] The indium-bipyridinyl-catalysed enantioselective ring-opening of meso -epoxides of ci s-stilbene, cis -1,2-naphthylethylene, cis -3,3′-dimethylstilbene, cis -4,4′-dimethylstilbene and cis -4,4′-dichloro stilbene in benzylthiol, phenylthiol, 4-methyl phenylthiol, ethylthiol, n -butylthiol and 1-methyl butylthiol resulted in 1,2-mercapto alcohols in good yields (67–91%) and moderate to good enantioselectivities (85–96%). The optimised reaction condition utilised 10 mol% of InBr 3 , 11 mol % of the bipyridinyl diol 148 in CH 2 Cl 2 at room temperature.…”

β-Hydroxy sulfides and their syntheses

“…Schneider and co-workers reported the same scandium–bipyridine complex as excellent catalyst for the thiolysis and selenolysis of meso -epoxides to give the corresponding β-hydroxy derivatives in good yields and high enantioselectivities, in dichloromethane as the solvent [ 47 – 48 ]. As an extension to this work, a novel chiral 2,9-disubstituted-1,10-phenanthroline 54 was prepared by the same group and its utility in the enantioselective ring-opening of cis -stilbene oxide with aniline and thiophenol was demonstrated.…”

Catalytic Enantioselective Ring-Opening Reaction of meso-Epoxides with ArSeH Using a (Salen)Ti(IV) Complex

“…Over past several decades, various nucleophiles such as RNH 2 [2,3], ROH [4], TMSCN [5], RN 3 [6], and RSH [7,8] have been widely investigated in the reaction catalyzed by various chiral catalysts to obtain 1,2-amino alcohols, 1,2-diol monoethers, 1,2-cyano alcohols, 1,2-azidoalcohols, as well as 1,2-mercaptoalcohols, respectively [9,10]. Chiral organoselenium compounds have been employed as useful ligands, catalysts, or intermediates in various asymmetric transformations such as diethylzinc addition to aldehydes, asymmetric hydrosilylation, and 1,4-addition of Grignard reagents to enones [11][12][13].…”