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Upstream product

• 536-74-3 phenylacetylene 
• 1137-96-8 N-(benzylidene)aniline N-oxide 
• 18101-13-8 2,3,5-triphenyl-thiazolidin-4-one 
• 201024-81-9 C,N-diphenylnitrone 

Relevant academic research and scientific papers

Studies on the Enantioselective Kinugasa Reaction: Efficient Synthesis of β-Lactams Catalyzed by N-PINAP/CuX Complexes

Catalytic enantioselective Kinugasa reactions between acyclic and, for the first time, cyclic nitrones and terminal alkynes are described herein. A catalytic amount of the readily available PINAP/CuX complexes, generated in situ, efficiently catalyzed the Kinugasa reactions, leading to a series of β-lactams with good enantioselectivities and moderate diastereoselectivities and yields. A broad range of nitrones and terminal alkynes, including the seldom reported alkyl-substituted alkynes, were tolerated under the reaction conditions. Further investigations proved that the PINAP/CuX catalytic system enabled the synthesis of monobactams on the gram scale (without loss of stereoselectivity and yield) and also both enantiomers by the appropriate choice of readily available atropisomeric N-PINAP ligands.

Development of TsDPEN based imine-containing ligands for the copper-catalysed asymmetric Kinugasa reaction

A novel class of chiralN,N,Nimine-containing ligands derived from TsDPEN (N-(p-tosyl)-1,2-diphenylethylene-1,2-diamine) has been developed and applied to the copper-catalyzed asymmetric Kinugasa reaction. The copper(ii) salt proved to be an efficient catalyst precursor, and it provides an efficient way to synthesize enantioenrichedcis-β-lactam. The pathway is air-tolerant and easily manipulated, and the ligands are easy to synthesize. A working model is proposed in which the stereocontrolling step is the [2 + 2] cycloaddition between ketene and imine to explain the observed stereoselectivities.

Asymmetric synthesis of trans-β-lactams by a Kinugasa reaction on water

The asymmetric Kinugasa reaction was performed on pure water for the first time without the need for any organic co-solvents. In contrast to most asymmetric Kinugasa reactions, trans-β-lactams were obtained as the major products in good yields, enantioselectivities, and diastereoselectivities (up to 90 % yield, 98 % ee, and >99:1 d.r.). This reaction is atom-economical, environmentally friendly, and affords synthetically useful but challenging products. Walking on water: Asymmetric Kinugasa reactions on pure water without any organic co-solvents afforded synthetically useful trans-β-lactams in good yields, enantioselectivities, and diastereoselectivities (up to 90 % yield, 98 % ee, and >99:1 d.r.). Copyright

Tris(oxazoline)/copper-catalyzed coupling of alkynes with nitrones: A highly enantioselective access to β-lactams

Chiral tris(oxazoline)/Cu(I) complexes are demonstrated as a type of efficient catalysts for the asymmetric Kinugasa reaction of terminal alkynes with C-arylnitrones, providing a highly enantio- and diastereoselective access to optically active β-lactams.

Enantioselective synthesis of β-lactams via the IndaBox-Cu(II)-catalyzed Kinugasa reaction

The enantioselective Kinugasa reaction of nitrones with terminal alkynes in the presence of 20 mol % of IndaBox-Cu(OTf)2 and di-sec-butylamine (1.5 equiv) produced β-lactams with the highest level of enantiomeric excesses among the catalytic en

Trisoxazoline/Cu(II)-promoted Kinugasa reaction. Enantioselective synthesis of β-lactams

The reactions of nitrones with terminal alkynes, catalyzed by chiral iPr-trisoxazoline 23/Cu(ClO4)2·6H 2O under air atmosphere, afforded β-lactams in moderate to good yields with up to 85% ee. The diastereoselec

Chiral tris(oxazoline)/Cu(II) catalyzed coupling of terminal alkynes and nitrones.

Novel chiral iPr-tris(oxazoline)/Cu(ClO4)2 x 6H2O catalyzed coupling of terminal acetylenes and nitrones to afford cis-disubstituted beta-lactams is described; the choice of base proves essential to both the diastereoselectivity and the enantioselectivity

Cu(I)/Bis(azaferrocene)-catalyzed enantioselective synthesis of β-lactams via couplings of alkynes with nitrones

As a consequence of the wide-ranging significance of β-lactams (e.g., use as drugs and as chiral building blocks), a great deal of effort has been dedicated to the development of methods for their stereoselective synthesis. Although considerable progress has been achieved, nearly all of the approaches that have been described are based on the use of chiral precursors; direct catalytic enantioselective routes to β-lactams are rare as well as limited in scope. In this communication, we establish that, using a new C2-symmetric planar-chiral bis(azaferrocene) ligand, we can generate β-lactams with very good enantiomeric excess and cis diastereoselection via catalytic enantioselective Kinugasa reactions (couplings of alkynes with nitrones). Appealing attributes of this process include the ready availability of the starting materials, the functional-group tolerance of the reaction, and the convergency of the approach. Copyright

Reductive Ring Contraction of Mesoionic Thiazol-4-ones to Azetidin-2-ones

A series of anhydro-2,3,5-triaryl-4-hydroxythiazolium hydroxides was prepared and desulfurized with Raney nickel.The reduction was stereospecific and gave cis-1,3,4-triphenylazetidin-2-ones.Desulfurization in the presence of triphenylphosphine gave the corresponding trans-azetidinones.Consideration of the possible mechanistic pathways led to the conclusion that the reaction proceeds through formation of biradical-dipole, hydrogenation to a 1,4-dipole, and ring closure.It was also concluded that in the preparation of β-lactams by the nonconcerted cycloaddition of imines and ketenes the first step (dipole formation) is the stereochemistry-determining step.