The parent Josiphos ligand gave excellent ee values (95-99%) and good yields (60-97%) in the copper-catalysed asymmetric conjugate reduction of β-aryl α,β-unsaturated lactones and lactams with PMHS. The substrates were obtained from stereospecific copper-catalysed addition of arylboronic acids to alkynoates followed by deprotection and cyclisation. The acyclic lactam precursors also underwent reduction with good ee values (83-85%) and yields (79-95%). Application of this asymmetric reduction methodology included the synthesis of natural product lucidulactone A.
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http://dx.doi.org/10.1039/d3ob00563a | DOI Listing |
Stereochemical-controlled hydrogen bond donors play essential roles in the pharmaceutical industry. Consequently, organic molecules that bear difluoromethyl (CF2H) groups at chiral centers are emerging as pivotal components in pharmaceuticals due to their distinct hydrogenbonding property. However, a general approach for introducing CF2H groups in an enantioselective manner remained elusive.
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August 2024
Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, Ministry of Education. State Key Laboratory of Green Pesticide, College of Chemistry, Central China Normal University, Wuhan, 430079, China.
The construction of atropisomers with 1,2-diaxes, while maintaining high enantiocontrol, presents a significant challenge due to the dynamic nature of steric hindrance at ortho-aryl substituents. Although various catalytic asymmetric methods have been developed for accessing axially chiral arylpyrroles, the synthesis of axially chiral arylpyrroles with 1,2-diaxes in a catalytic asymmetric manner has remained rare. Herein, the authors report the synthesis of diverse axially chiral arylpyrroles with 1,2-diaxes, and C-C and C-N axes through copper-catalysed asymmetirc [4 + 1] annulation of yne-allylic esters with arylamines via a remote stereocontrol strategy.
View Article and Find Full Text PDFNat Chem
August 2024
Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry at Fuzhou University, Fuzhou, Fujian, China.
Bioisosteric replacement has emerged as a clear strategy for drug-structure optimization. Naphthalene is the core element of many chiral pharmaceuticals and drug candidates. However, as a promising isostere of naphthalene, the chiral version of 1,2-benzazaborine has rarely been explored due to the lack of efficient synthetic methods.
View Article and Find Full Text PDFNat Chem
April 2024
Department of Chemistry, Virginia Commonwealth University, Richmond, VA, USA.
Nat Chem
March 2024
Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, China.
Although α-chiral C(sp)-S bonds are of enormous importance in organic synthesis and related areas, the transition-metal-catalysed enantioselective C(sp)-S bond construction still represents an underdeveloped domain probably due to the difficult heterolytic metal-sulfur bond cleavage and notorious catalyst-poisoning capability of sulfur nucleophiles. Here we demonstrate the use of chiral tridentate anionic ligands in combination with Cu(I) catalysts to enable a biomimetic enantioconvergent radical C(sp)-S cross-coupling reaction of both racemic secondary and tertiary alkyl halides with highly transformable sulfur nucleophiles. This protocol not only exhibits a broad substrate scope with high enantioselectivity but also provides universal access to a range of useful α-chiral alkyl organosulfur compounds with different sulfur oxidation states, thus providing a complementary approach to known asymmetric C(sp)-S bond formation methods.
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