Xiao Long Zhao

Bio: Xiao Long Zhao is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Enantioselective synthesis & Trifluoromethyl. The author has an hindex of 1, co-authored 2 publications receiving 75 citations.

Highly Enantioselective Construction of a Quaternary Carbon Center of Dihydroquinazoline by Asymmetric Mannich Reaction and Chiral Recognition

Abstract: The highly enantioselective construction of a quaternary carbon center of dihydroquinazoline by an asymmetric Mannich reaction and chiral recognition are described The key transformation was to establish the chiral trifluoromethyl quaternary carbon center by a diamine-Bronsted acid-catalyzed enantioselective and regioselective Mannich reaction of a methyl ketone and 4-trifluoromethyldihydroquinazoline An unusual phenomenon of self-discrimination of enantiomers in hydrogen-bonded dimers was observed A valuable intermediate was transformed into the enantiopure HIV reverse transcriptase inhibitor DPC 083 (>999 ee) simply by reduction of the carbonyl group and elimination of the hydroxy group in hexamethylphosphoric tramide (HMPA)

Highly Enantioselective Construction of a Quaternary Carbon Center of Dihydroquinazoline by Asymmetric Mannich Reaction and Chiral Recognition.

Abstract: The highly enantioselective construction of a quaternary carbon center of dihydroquinazoline by an asymmetric Mannich reaction and chiral recognition are described. The key transformation was to establish the chiral trifluoromethyl quaternary carbon center by a diamine-Bronsted acid-catalyzed enantioselective and regioselective Mannich reaction of a methyl ketone and 4-trifluoromethyldihydroquinazoline. An unusual phenomenon of self-discrimination of enantiomers in hydrogen-bonded dimers was observed. A valuable intermediate was transformed into the enantiopure HIV reverse transcriptase inhibitor DPC 083 (>99.9 ee) simply by reduction of the carbonyl group and elimination of the hydroxy group in hexamethylphosphoric tramide (HMPA).

Asymmetric construction of stereogenic carbon centers featuring a trifluoromethyl group from prochiral trifluoromethylated substrates.

Abstract: Department of Chemistry, Tianjin University, Tianjin 300072, China; Department of Applied Chemistry, China Agricultural University, Beijing 100193, China; UMR 6014 CNRS, Laboratoire COBRA de l’IRCOF, Université et INSA de Rouen, Rue Tesniere, F-76130 Mont Saint Aignan, France; and Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, Shanghai 200032, China

Enantioselective Synthesis of AG‐041R by using N‐Heteroarenesulfonyl Cinchona Alkaloid Amides as Organocatalysts

Abstract: The organocatalytic enantioselective decarboxylative addition of malonic acid half thioesters to ketimines derived from isatins by using N-heteroarenesulfonyl cinchona alkaloid amides afforded products with high enantioselectivity. The products could be converted into optically active AG-041R. X-ray crystallographic analysis revealed that the hydrogen bonding between the sulfonimide proton and the 8-quinolyl nitrogen atom plays an important role in exerting the enantioselectivity of the reaction.

Asymmetric organocatalysis: an enabling technology for medicinal chemistry

Abstract: The efficacy and synthetic versatility of asymmetric organocatalysis have contributed enormously to the field of organic synthesis since the early 2000s. As asymmetric organocatalytic methods mature, they have extended beyond the academia and undergone scale-up for the production of chiral drugs, natural products, and enantiomerically enriched bioactive molecules. This review provides a comprehensive overview of the applications of asymmetric organocatalysis in medicinal chemistry. A general picture of asymmetric organocatalytic strategies in medicinal chemistry is firstly presented, and the specific applications of these strategies in pharmaceutical synthesis are systematically described, with a focus on the preparation of antiviral, anticancer, neuroprotective, cardiovascular, antibacterial, and antiparasitic agents, as well as several miscellaneous bioactive agents. The review concludes with a discussion of the challenges, limitations and future prospects for organocatalytic asymmetric synthesis of medicinally valuable compounds.

Hydrogen-Bond-Directed Enantioselective Decarboxylative Mannich Reaction of β-Ketoacids with Ketimines: Application to the Synthesis of Anti-HIV Drug DPC 083

Abstract: This is the first hydrogen-bond-directed enantioselective decarboxylative Mannich reaction of β-ketoacids with ketimines affording quinazolinone derivatives with quaternary stereocenters in high yields and with excellent enantioselectivities using saccharide-based amino-thiourea organocatalysts.