Cascade Reaction by Chemo‐ and Biocatalytic Approaches to Obtain Chiral Hydroxy Ketones and anti 1,3‐Diols

Abstract

A chemo‐ and biocatalytic cascade approach was applied for the stereoselective synthesis of hydroxy ketones and the corresponding 1,3‐diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β‐borylation of α,β‐unsaturated compounds. The complex containing ligand L5 emerged as the best performer, and it gave the organoborane derivatives with good ee values. The corresponding keto–alcohol compounds were then bioreduced by yeasts. The biotransformation set up with Rhodotorula rubra allowed (R)‐keto–alcohols and (S,S)‐diols to be obtained with up to 99 % ee and up to 99 % de in favor of the anti enantiomers.

Asymmetric Hydrogenation of 1-aryl substituted-3,4-Dihydroisoquinolines with Iridium Catalysts Bearing Different Phosphorus-Based Ligands

“…Based on our experience in the use of the chiral 8-amino-5,6,7,8-tetrahydroquinoline scaffold and its derivatives as ligands in transition metal complexes, and considering their employment as sources of chirality in organometallic catalysts for asymmetric reduction or for C-B bond formation reactions [38][39][40], we decided to focus our attention on the synthesis of three amino monophosphine ligands: amino-phosphine (L1), -phosphinite (L2) [41,42] and -phosphite (L3). For the synthesis of amino monophosphines, we started from the chiral 5,6,7,8-tetrahydroquinolin-ol, the enantiomers of which were successfully separated through enzymatic DKR by Candida antarctica lipase B with high yield and purity [43].…”

Antiproliferative effects of chalcones on T cell acute lymphoblastic leukemia‐derived cells: Role of PKCβ

“…Chalcone derivatives were synthesized using the synthetic methodology previously described. [30,31] Briefly, an aqueous solution of sodium hydroxide was added slowly to a methanol solution of the appropriate acetophenone. After the solution was cooled to room temperature, the appropriate benzaldehyde was added.…”

Exploring the copper binding ability of Mets7 hCtr‐1 protein domain and His7 derivative: An insight in Michael addition catalysis

“…[10][11][12][13][14][15][16] Conversely, enzymes often outperform transition metal catalysts with higher levels of efficiency and of chemoselectivity, regioselectivity and stereoselectivity, [17][18][19][20] giving thus an inspiration for the development of enzyme-like transition metal hybrid catalysts. [19][20][21][22][23] Combining the rational design of the peptide ligand and the choice of an appropriate metal, it is possible to merge the high reactivity of transition metals with the structural and functional groups versatility of peptides, achieving levels of reactivity otherwise unrealisable. A common approach in this regard takes advantage of natural peptide sequences known for their ability to coordinate to metal ions.…”

“…Indeed, despite the achievements obtained using transition metal catalysts based on chiral diphosphines and N ‐chelating ligands, many transformations are still hampered by several issues concerning reactivity and selectivity 10–16 . Conversely, enzymes often outperform transition metal catalysts with higher levels of efficiency and of chemoselectivity, regioselectivity and stereoselectivity, 17–20 giving thus an inspiration for the development of enzyme‐like transition metal hybrid catalysts 19–23 . Combining the rational design of the peptide ligand and the choice of an appropriate metal, it is possible to merge the high reactivity of transition metals with the structural and functional groups versatility of peptides, achieving levels of reactivity otherwise unrealisable.…”