1466-83-7Relevant articles and documents
Inclusion complexes of N-benzoyl-D-leucine and N-benzoyl-L-leucine with β-cyclodextrin by Raman spectroscopy
Spivey, Robin,Swofford, Robert L.
, p. 435 - 438 (1999)
We report what is believed to be the first detection of chiral recognition in the inclusion complexes of cyclodextrins by Raman spectroscopy. The spectra of inclusion complexes of N-benzoyl-D-leucine or N-benzoyl-L-leucine with β-cyclodextrin were recorded in the 1500-1800 and 3000-3150 cm-1 regions. These chiral molecules were chosen to provide group frequencies (NH2(+) and benzoyl C=O) near the chiral center of the guest as well as COO- and phenyl CH for probing the guest molecule without spectral interference from the vibrational bands of the cyclodextrin host. Frequency shifts and intensity decreases were observed for some Raman bands of N-benzoyl-leucines upon inclusion in the cyclodextrin cavity. In the Raman spectra of the inclusion complex, the frequency shifts were greater for N-benzoyl-D-leucine than for N-benzoyl-L-leucine.
Nickel-Catalyzed Multicomponent Coupling: Synthesis of α-Chiral Ketones by Reductive Hydrocarbonylation of Alkenes
Chen, Jian,Zhu, Shaolin
supporting information, p. 14089 - 14096 (2021/09/13)
A nickel-catalyzed, multicomponent regio- and enantioselective coupling via sequential hydroformylation and carbonylation from readily available starting materials has been developed. This modular multicomponent hydrofunctionalization strategy enables the straightforward reductive hydrocarbonylation of a broad range of unactivated alkenes to produce a wide variety of unsymmetrical dialkyl ketones bearing a functionalized α-stereocenter, including enantioenriched chiral α-aryl ketones and α-amino ketones. It uses chiral bisoxazoline as a ligand, silane as a reductant, chloroformate as a safe CO source, and a racemic secondary benzyl chloride or an N-hydroxyphthalimide (NHP) ester of a protected α-amino acid as the alkylation reagent. The benign nature of this process renders this method suitable for late-stage functionalization of complex molecules.
Rh(iii)-Catalyzed diastereoselective transfer hydrogenation: An efficient entry to key intermediates of HIV protease inhibitors
Chen, Gen-Qiang,Lang, Qi-Wei,Phansavath, Phannarath,Ratovelomanana-Vidal, Virginie,Wang, Fangyuan,Wu, Ting,Yin, Congcong,Zhang, Xumu,Zheng, Long-Sheng
, p. 3119 - 3122 (2020/03/23)
A highly efficient diastereoselective transfer hydrogenation of α-aminoalkyl α′-chloromethyl ketones catalyzed by a tethered rhodium complex was developed and successfully utilized in the synthesis of the key intermediates of HIV protease inhibitors. With the current Rh(iii) catalyst system, a series of chiral 3-amino-1-chloro-2-hydroxy-4-phenylbutanes were produced in excellent yields and diastereoselectivities (up to 99% yield, up to 99?:?1 dr). Both diastereomers of the desired products could be efficiently accessed by using the two enantiomers of the Rh(iii) catalyst.
Asymmetric construction of dihydrobenzofuran-2,5-dione derivatives via desymmetrization of p-quinols with azlactones
Xie, Lihua,Dong, Shunxi,Zhang, Qian,Feng, Xiaoming,Liu, Xiaohua
supporting information, p. 87 - 90 (2019/01/03)
The desymmetrization of p-quinols through a chiral bisguanidinium hemisalt catalyzed enantioselective Michael addition/lactonization cascade reaction with azlactones was reported. 3-Amino-benzofuran-2,5-diones containing a chiral amino acid residue were achieved with up to 99% ee and >19?:?1 dr. An exploration of the structure of the catalyst bisguanidinium was undertaken, revealing a bifunctional catalytic model.
