Jin-Tao Liu

Asymmetric aza-Henry reaction of chiral fluoroalkyl α,β-unsaturated N-tert-butanesulfinyl ketoimines: an efficient approach to enantiopure fluoroalkylated α,β-diamines and α,β-diamino acids

The aza-Henry reaction of chiral fluoroalkyl α,β-unsaturated N-tert-butanesulfinyl ketoimines and nitromethane was achieved in the presence of 0.2 equivalent of anhydrous potassium carbonate to give the corresponding adducts diastereoselectively in high yields. Transformations which highlighted the synthetic potential of these aza-Henry adducts were also performed.

Copper-Catalyzed Intramolecular Carbotrifluoromethylation of Alkynes for the Construction of Trifluoromethylated Heterocycles

A mild and efficient copper-catalyzed intramolecular carbotrifluoromethylation of alkynes has been achieved in the presence of Togni reagent as trifluoromethylating reagent. The reaction tolerates a range of substrates to give a group of trifluoromethylated heterocycles with high selectivities. A plausible mechanism was proposed on the basis of experimental results.

Copper-Catalyzed Regioselective Reaction of Internal Alkynes and Diaryliodonium Salts

The copper-catalyzed highly regioselective reaction of internal alkynes with diaryliodonium salts was achieved for the first time. α-Arylketones were obtained in moderate to good yields from arylpropargylic alcohols or aryl alkyl alkynes under mild conditions. It was found that the two kinds of substrates underwent two different arylation-oxygenation pathways under different reaction conditions based on deuterated experiments, controlling experiments, and spectroscopic analysis of reaction intermediates.

Optically pure polyfluoroalkanesulfinamides: synthesis and application as promising and monitorable chiral auxiliaries.

Efficient synthesis of enantiopure polyfluoroalkanesulfinamides (PFSAs) has been achieved. Their application as novel chiral auxiliaries with an electron-withdrawing and (19)F NMR monitorable polyfluoroalkyl group was initially demonstrated in an asymmetric Strecker reaction under mild conditions.

SODIUM DITHIONITE INITIATED ADDITION-SULFINATION REACTION OF PERFLUOROALKYL BROMIDES AND OLEFINS

Abstract In the presence of sodium dithionite, perfluoroalkyl bromides reacted with olefins readily in aqueous iso-propanol solution under mild conditions, giving the corresponding addition–sulfination products, R F CH 2 CH(R)SO 2 Na, in good yields. A radical mechanism was proposed for this reaction.

THE REACTION OF SODIUM PERFLUOROALKANESUFINATES WITH COUMARIN

Abstract The reaction of sodium perfluoroalkanesufinates with coumarin in the presence of Mn(OAc) 3 ·2H 2 O was studied. Sodium perfluoroalkanesufinates, R F SO 2 Na [R F =F(CF 2 ) 6 , 2a ; F(CF 2 ) 7 , 2b ; F(CF 2 ) 8 , 2c ; Cl(CF 2 ) 4 , 2d ; Cl(CF 2 ) 6 , 2e ], reacted readily with a small excess of coumarin to give the corresponding 3-perfluoroalkylated coumarins ( 3a – e ), while poly-perfluoroalkylation of coumarin occurred when excess 2 was used in the reaction, and 3,6-diperfluoroalkylcoumarins ( 4 ) and 3,6,8-triperfluoroalkylcoumarins ( 5 ) were isolated as major products according to the ratio of starting materials.

Copper-catalyzed stereoselective oxytrifluoromethylation of propargyl amides for the construction of oxazolines

The copper-catalyzed stereoselective oxytrifluoromethylation of terminal propargyl amides took place readily in the presence of Tognis reagent under mild conditions, giving the corresponding trifluoromethylated oxazoline derivatives in moderate to good yields. Using CuBr as catalyst, the E-isomer was obtained as major product. However, the formation of Z-isomer with excellent stereoselectivity was also achieved while Cu(CH3CN)4PF6 was used. Plausible pathways are proposed to account for the excellent stereoselectivity of the reaction.

Copper-catalyzed regio- and stereoselective O-arylation of enolates.

Copper-catalyzed O-arylation of enolates with diaryliodonium salts as arylating reagents was realized successfully. As important building blocks, β-aryloxy carbonyl compounds were obtained in up to 98% yield under mild conditions, and complete control of O-arylation and Z-stereoselectivity were achieved. The origin of the selectivity was also discussed.

THE REACTION OF PERFLUOROALKANESULFINATES. IX: PERFLUOROALKYLATION OF PYRIDINE AND ITS DERIVATIVES WITH SODIUM PERFLUOROALKANESULFINATES

Abstract The reaction of pyridine and its derivatives with sodium perfluoroalkanesulfinates (R F SO 2 Na) in the presence of Mn(OAc) 3 is reported. Pyridines react with this reagent system readily to give the corresponding perfluoroalkylated products as a mixture of isomers with moderate yield. However, reaction of quinoline and isoquinoline under similar conditions gives the C(5)- and C(8)-substituted products regioselectively.

The synthesis and strecker reaction of 2-chlorotetrafluoroethanesulfinyl ketimines.

A series of 2-chlorotetrafluoroethanesulfinyl ketimines were prepared from 2-chlorotetrafluoroethanesulfinamide and ketones in high yields, and their Strecker reactions with TMSCN have been investigated. High yields and excellent diastereoselectivities were achieved in the presence of a catalytic amount of CsF under mild conditions. The six-membered chairlike models were proposed to account for the high stereoselective Strecker reaction.