345217-87-0Relevant articles and documents
A flexible strategy for the synthesis of bifunctional 6′-(thio)-urea containing Cinchona alkaloid ammonium salts
Sch?rgenhumer, Johannes,Otte, Stefan,Haider, Victoria,Novacek, Johanna,Waser, Mario
, (2020)
A flexible and functional group tolerant synthesis route to access a structurally diverse collection of bifunctional 6′-(thio)-urea containing Cinchona alkaloid-based chiral quaternary ammonium salts has been developed. This route gives access to more than 25 different novel urea- and thiourea-containing ammonium salt derivatives, which were not accessible so far.
Highly enantioselective amination of α-substituted α-cyanoacetates with chiral catalysts accessible from both quinine and quinidine
Liu, Xiaofeng,Li, Hongming,Deng, Li
, p. 167 - 169 (2005)
(Chemical Equation Presented) The catalytic construction of nitrogen-substituted quaternary stereocenters is an important and challenging task in asymmetric synthesis. In this paper, we describe the use of 6′-OH-modified cinchona alkaloids that are accessible from either quinine or quinidine for the development of a highly enantioselective amination of α,α-disubstituted carbonyl compounds that is suitable for the creation of nitrogen-substituted quaternary stereocenters in either the R or S configuration.
Enantioselective Ammonium Ylide Mediated One-Pot Synthesis of Highly Substituted γ-Butyrolactones
Drennhaus, Till,?hler, Laura,Djalali, Saveh,H?fmann, Svenja,Müller, Clemens,Pietruszka, J?rg,Worgull, Dennis
supporting information, p. 2385 - 2396 (2020/04/30)
An ammonium ylide mediated access towards trans-β,γ-disubstituted, all-trans-α,β,γ-trisubstituted, and α,α,β,γ-tetrasubstituted γ-butyrolactones bearing a broad variety of functionalities was developed. Starting from widely accessible benzylidene Meldrum's acid derivatives and α-bromo carbonyl compounds, γ-butyrolactones were obtained in yields between 32–99% with up to excellent diastereoselectivities (>95:5) via a DABCO-mediated [2+1] annulation. Utilization of enantiomerically pure cinchona alkaloid derivatives enables the first asymmetric ammonium ylide mediated method to provide (3R,?4R)-β,γ-disubstituted and (2R,?3R,?4R)-α,β,γ-trisubstituted γ-butyrolactones in moderate to good yields with up to very good enantiomeric ratios (97:3). The scalability of the transformation was proven while determining the absolute configuration. (Figure presented.).
Metal-Free, Phosphonium Salt-Mediated Sulfoximination of Azine N-Oxides: Approach for the Synthesis of N-Azine Sulfoximines
Aithagani, Sravan Kumar,Kumar, Mukesh,Yadav, Mahipal,Vishwakarma, Ram A.,Singh, Parvinder Pal
, p. 5886 - 5894 (2016/07/23)
Herein, we report a simple and metal-free method for the synthesis of N-azine sulfoximines by the nucleophilic substitution of azine N-oxides with NH-sulfoximines. The present method works at room temperature with wide functional group compatibility and gives several unprecedented N-azine sulfoximines. The reaction conditions were also found suitable with enantiopure substrates and furnished products without any racemization. It also finds an application in the sulfoximination of azine-based functional molecules such as 2,2′-bipyridine, 1,10-phenanthroline, and quinine.
