26666-96-6

Upstream product

• 936694-43-8 6'-methoxycinchonan-9-ol 
• 56-54-2 qunidine 
• 522-66-7 dihydroquinine 
• 889449-48-3 9-mesyloxydihydroquinine 

Downstream Products

• 144864-96-0 Dihydroquinidine 4-vinylbenzoate 
• 144864-96-0 Dihydroquinine 4-vinylbenzoate 
• 931098-91-8 9-epi-9-amino-9-deoxy-dihydroquinidine trihydrochloride 

Relevant academic research and scientific papers

Catalytic Enantio- and Diastereoselective Mannich Addition of TosMIC to Ketimines

Chiral amines bearing a stereocenter in the α position are ubiquitous compounds with many applications in the pharmaceutical and agrochemical sectors, as well as in catalysis. Catalytic asymmetric Mannich additions represent a valuable method to access such compounds in enantioenriched form. This work reports the first enantio- and diastereoselective addition of commercially available p-toluenesulfonylmethyl isocyanide (TosMIC) to ketimines, affording 2-imidazolines bearing two contiguous stereocenters, one of which is fully-substituted, with high yields and excellent stereocontrol. The reaction, catalyzed by silver oxide and a dihydroquinine-derived N,P-ligand, is broad in scope, operationally simple, and scalable. Derivatization of the products provides enantioenriched vicinal diamines, precursors to NHC ligands and sp3-rich heterocyclic scaffolds. Computations are used to understand catalysis and rationalize stereoselectivity.

Organocatalytic asymmetric direct vinylogous Michael addition of α,β-unsaturated γ-butyrolactam to nitroolefins

The first organocatalytic enantioselective direct vinylogous Michael reaction of α,β-unsaturated γ-butyrolactam to nitroolefins is developed using cinchona alkaloids as the catalysts. Both product enantiomers are accessible with moderate to good enantioselectivity.

Simple enantiospecific synthesis of sulfides of Cinchona alkaloids

The native and epi-Cinchona alkaloids were reacted with (ArS) 2/Bu3P in toluene at 65 °C to give the corresponding arylsulfanyl derivatives (15 examples, 31-75%) with complete inversion of configuration at 9-C stereogenic centers. Similar products were also obtained in the enantiospecific nucleophilic substitution of the 9-mesylates of alkaloids with sodium thiolates (4 examples, 73-84%) and no cinchona rearrangement was observed. The chiral thioethers obtained were preliminarily tested as N(sp 3), S-donating chiral ligands in the Pd-catalyzed allylic alkylation of dimethyl malonate with rac-1,3-diphenylprop-2-enyl acetate and gave the product with up to 78% ee. Georg Thieme Verlag Stuttgart.

Heterogeneous enantioselective hydrogenation of ethyl pyruvate catalyzed by cinchona-modified Pt catalysts: Effect of modifier structure

The effect of the structure of chiral modifiers derived from natural cinchona alkaloids on the enantioselectivity and rate of the Pt/Al2O3-catalyzed hydrogenation of ethyl pyruvate was investigated. The influence of the following structural elements was studied: The cinchonidine versus the cinchonine backbone; effect of the nature and the size of substituents attached to C9; effect of partial hydrogenation of the quinoline ring; effects of changes of the substituent at the quinuclidine moiety. The strongest effects on ee and somewhat less on rate were observed for changes in the O-C9-C8-N part of the cinchona alkaloid and for partial or total hydrogenation of the quinoline rings. The nature of the substituents in the quinuclidine part had a comparably minor influence. The solvent was found to have a significant effect on enantioselectivity and rate. In acetic acid, the best results were obtained with O-methyl-10,11-diydrocinchonidine (ee's up to 93%), whereas dihydrocinchonidine was the most effective modifier in toluene. In agreement with a basic model proposed by Pfaltz, it was concluded that the minimal-requirements for an efficient modifier for the hydrogenation of α-keto esters is the presence of a basic nitrogen center close to one or more stereogenic centers and connected to an aromatic system. The results are in qualitative agreement with mechanistic models based on hydrogen-bonding interactions between an adsorbed modifier molecule and adsorbed ethyl pyruvate or its half-hydrogenated intermediate.