91645-74-8

Upstream product

• 1115-59-9 (S)-alanine ethyl ester hydrochloride 
• 98-59-9 p-toluenesulfonyl chloride 
• 4816-81-3 p-tosyl-L-alanine 
• 64-17-5 ethanol 
• 3082-75-5 L-Alanine ethyl ester 
• 17344-99-9 AlaOEt 
• 141-52-6 sodium ethanolate 
• 87023-89-0 N-(1-(3,5-dimethyl-1H-pyrazol-1-yl)-1-oxopropan-2-yl)-4-methylbenzenesulfonamide 

Downstream Products

• 197247-26-0 N-p-toluenesulfonyl-L-alaninal 

Relevant academic research and scientific papers

Enantioselective [3 + 2] Annulation of Enals with 2-Aminoacrylates Catalyzed by N-Heterocyclic Carbene

A novel and convenient strategy for the enantioselective synthesis of γ-lactam derivatives via N-heterocyclic carbene catalyzed formal [3 + 2] annulation of enals with 2-aminoacrylates is disclosed. This activation mode provides a complementary approach to the synthesis of various γ-lactam derivatives in good yields with excellent diastereo- and enantioselectivities. In this process, two consecutive stereocenters are constructed, and a quaternary carbon center is also established.

Direct Catalytic Chemoselective α-Amination of Acylpyrazoles: A Concise Route to Unnatural α-Amino Acid Derivatives

A direct copper-catalyzed highly chemoselective α-amination is described. Acylpyrazole proved to be a highly efficient enolate precursor of a carboxylic acid oxidation state substrate, while preactivation by a stoichiometric amount of strong base has been used in catalytic α-aminations. The simultaneous activation of both coupling partners, enolization and metal nitrenoid formation, was crucial for obtaining the product, and wide functional group compatibility highlighted the mildness of the present catalysis. The bidentate coordination mode was amenable to highly chemoselective activation over ketone and much more acidic nitroalkyl functionality. Deuterium exchange experiments clearly demonstrated that exclusive enolization of acylpyrazole was achieved without the formation of a nitronate. The present catalysis was applied to late-stage α-amination, allowing for concise access to highly versatile α-amino acid derivatives. The product could be transformed into variety of useful building blocks.

Tandem intramolecular hydroalkoxylation-hydroarylation reactions: Synthesis of enantiopure benzofused cyclic ethers from the chiral pool

A highly efficient and general method for the diastereoselective synthesis of benzo-fused eight-membered carbo- and heterocycles was studied. The method is based on a new tandem gold- or platinum catalyzed hydroalkoxytion- hydroarylation reaction. The use

Acyclic stereoselection in the tertiary amine-catalysed addition of activated vinyl systems (Baylis-Hillman reaction) to protected chiral α-hydroxy and α-amino aldehydes

The non chelation-controlled aldol-type addition of the ambident vinyl α anions derived from acrylic esters and methyl vinyl ketone to a series of protected chiral α-hydroxy and α-amino aldehydes has been investigated in order to assess some of the factors which contribute to the control of the diastereofacial selectivity.Whlist the α-methylene-β,γ-disubstituted carbonyl products showed a general preference for selectivity, some examples of syn predominance were made possible via a 'substituent tuning'approach.The observed diastereomer ratios have been interpreted in terms of the Felkin model and the Anh-Eisenstein proposals for 1,2-asymmetric induction.Simple steric effects appear to be as important as ?-orbital energies in the designation of the large 'anti group' for the application of these transition-state interpretations.Attempts to improve the overall induction via double diastereoselection approach, which combines the 1,5-induction of chiral acrylates with the 1,2-induction already present, were largely inconclusive.Methods for the routine NMR assignment of the relevant stereo-substructures have been assessed and the use of novel complementary technique is described.

Stereoselective Protonation of Carbanions, 4. Enantioselective Protonation of Lactone Enolates

The prochiral lithium enolates derived from the five-membered lactones rac-1 and rac-2 were protonated by 37 OH- and 21 NH-chiral proton sources in THF at -78 deg C.The enantioselectivities, determined directly from the reaction mixture by chiral HPLC, ar