New sp³ diphosphine-based rhodium catalysts for the asymmetric conjugate addition of aryl boronic acids to 3-azaarylpropenones

Abstract

Different chiral diphosphine ligands were successfully applied to the rhodium catalyzed asymmetric conjugate addition of differently substituted boronic acids to 3-azaarylpropenones containing both pyridinyl and imidazolyl cores. Atropoisomeric (S)-TetraMe-BITIANP (L1)...

Chiral 8-Amino-5,6,7,8-tetrahydroquinoline Derivatives in Metal Catalysts for the Asymmetric Transfer Hydrogenation of 1-Aryl Substituted-3,4-dihydroisoquinolines as Alkaloids Precursors

“…Moreover, the aqueous media usually employed in the ATH protocol generally avoid the use of the most performing but moisture sensitive diphosphine ligands, refs. [ 15 , 16 , 17 , 18 , 19 ] thus evoking the need for new catalysts able to broaden the scope toward the most challenging dihydroisoquinolines (DHIQs). The related reduction products, namely tetrahydroisoquinolines (THIQs), indeed account for an important class of alkaloids and semi-synthetic derivatives endowed with multiple relevant biological properties ( Figure 1 ) [ 20 , 21 , 22 , 23 , 24 ].…”

Exploitation of Dimeric Cyclic Cysteine as Helix Inducer in Ultra‐Short Peptides for Cu(II)‐Catalyzed Asymmetric Michael Addition on Chalcones

“…Chalcone containing pyridine 7 was synthesized as reported in literature [21] . In a capped vial containing Cu(OAc) 2 ⋅ H 2 O (10 % mol., 0.8 mg) and the ligand L1 or L2 (11 % mol) were added the substrate (1 mmol) and nitromethane (20 equiv.)…”

“…Chalcone containing pyridine 7 was synthesized as reported in literature. [21] In a capped vial containing Cu(OAc) 2 • H 2 O (10 % mol., 0.8 mg) and the ligand L1 or L2 (11 % mol) were added the substrate (1 mmol) and nitromethane (20 equiv.) and the resulting mixture was stirred at room temperature for 18 h then diluted with 400 μL of Et 2 O and 200 μL of H 2 O.…”

Hybrid Catalysts from Copper Biosorbing Bacterial Strains and Their Recycling for Catalytic Application in the Asymmetric Addition Reaction of B2(pin)2 on α,β-Unsaturated Chalcones

“…The use of this alternative and innovative strategy would give a second life to what has always been considered "waste" and therefore no longer useful. The so-formed hybrid catalysts are thus recycled in a representative copper catalyzed reaction, i.e., the asymmetric addition reaction of B 2 (pin) 2 on α,β-unsaturated chalcones, which are pharmaceutically related intermediates [18][19][20][21]. Chalcones are naturally synthesized in plants as secondary metabolites within the flavonoids' biosynthetic pathway, and their open-chain flavonoid structure features two aromatic rings joined by a three-carbon α,βunsaturated chain.…”