In Howa Jeong

Synthesis and SAR of sulfonyl- and phosphoryl amidine compounds as anti-resorptive agents.

Sulfonyl amidines (1) and phosphoryl amidines (2), which were efficiently synthesized via a Cu-catalyzed one pot reaction, showed potent anti-bone resorptive activity in vitro. Structure activity relationship studies led to the identification of numerous osteoclast differentiation inhibitors.

A novel approach to β-trifluoromethyl enaminones

Abstract— -Trifluoromethyl enaminones 1 were prepared in good yields from the reaction of trifluoropropynyl lithium with N -methoxy- N -methylbenzamide, followed by quenching with H 2 O in the presence of a variety of amines. The use of hydrazineor benzamidine as an amine source in this reaction resulted in the formation of pyrazole 3 or pyrimidine 4 .

Synthesis and biological activities of new fluorinated abscisic acid

Abstract A fluorinated analog of abscisic acid(ABA), which was prepared from 6-trifluoromethyl-2,6-dimethyl-2-cyclohexen-1,4-dione, showed potent inhibitory activities such as amylase induction in barley seeds and germination in cress seeds.

Preparation of α- or β-trifluoromethylated vinylstannanes and their cross-coupling reactions

Abstract α- or β-Trifluoromethylated vinylstannanes 1 , 2a , 3 and 4 were prepared form 1,1-bis(phenylthio)-2,2,3,3,3-pentafluoropropylbenzene ( 5 ) via several steps. The cross-coupling arylation reactions of 1 – 4 with aryl iodides bearing a bromo, methoxy, methyl, nitro or trifluoromethyl group on para- or meta-position of benzene ring afforded the corresponding coupling products in good yields. Compounds 1 , 2a and 4 underwent the acylation reaction with various types of acyl chlorides to give the corresponding trifluoromethylated enone derivatives in good yields. Reduction of trifluoromethylated enone derivatives with LiAlH 4 , followed by Fridel-Craft’s type of cyclization with AlCl 3 provided trifluoromethylated indene derivatives in good yields.

Efficient synthesis of novel α-aryl(alkyl)-β, β-difluorovinyl and α-aryl(alkyl)-β-fluoro-β-perfluoroalkylvinyl sulfides

Reaction of 1,1-vis(phenylthio)perfluoroalkyl aromatics or alkanes with a mixture of 2 equiv. of TiCl4 and 4 equiv. of LiAlH4 in THF at reflux temperature for 3 hours afforded α-aryl(alkyl)-β-fluoro-β-perfluoroalkylvinyl and α-aryl (alkyl)-β-fluoro-β-perfluoroalkylvinyl sulfides in good yields.

A study on the synthesis of antiangiogenic (+)-coronarin A and congeners from (+)-sclareolide.

Coronarin A 1, epi-coronarin A 2 and some synthetic intermediates 14a and 14b synthesized from sclareolide exhibit good growth inhibition activities on HUVEC proliferation. In particular, coronarin A 1 and epi-coronarin A 2 effectively suppressed the growth factor induced tube formation of HUVEC at the concentration of 10 micro g/mL.

Preparation of novel β,β-diphenyl α-(trifluoromethyl)vinylstannane and its cross-coupling reactions with aryl iodides

Abstract β,β-Diphenyl-α-(trifluoromethyl)vinylstannane 6 was prepared in good yield via several steps from 2,3,3,3-tetrafluoro-1-phenyl-1-phenylthiopropene. The cross-coupling reactions of 6 with aryl iodides in the presence of a catalytic amount of Pd(PPh 3 ) 4 and CuI provided trifluoromethylated triphenylethene derivatives 7 in high yields.

Preparation of 4-trifluoroethylidene-1,3-dioxolane derivatives via new stable (trifluoromethyl)ethynylation reagent

Abstract Perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2a – q were prepared in excellent yields from the reaction of new stable (trifluoromethyl)ethynylation reagent 1a with 1.3 equiv. of TBAF at −15°C for 10 min, followed by treatment with 2 equiv. of phenyl perfluoroalkylated ketone derivatives at room temperature. The reaction of 1a with 1.3 equiv. of TBAF, followed by treatment with 1 equiv. of aldehyde or ketone at −15°C for 10 min and then with trifluoroacetophenone (1 equiv.) at room temperature afforded perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2t – u in moderate yields.

Stereoselective methoxyselenenylation of acyclic allylic alcohol derivatives: A method for the synthesis of 1,3-anti-diols

Abstract Reaction of secondary acyclic trans -allylic alcohol derivatives with PhSeBr in the presence of 2,6-di- t -butylpyridine in MeOH proceeded in a highly regio- and stereoselective manner and the subsequent reduction and deprotection of the resultant methoxyselenides afforded mostly 1,3- anti -diols. The methoxyselenenylation of the acetate derivative of the same allylic alcohol, on the other hand, gave several other isomers along with the 1,3- anti -diol derivative.

A NEW METHOD FOR THE PREPARATION OF 2,3-DIARYL-1,1-DIFLUORO-1,3-BUTADIENES

Reactions of 1-trifluoromethyl-1,2-diarylvinyl sulfones 3 with aryllithium afforded aryl substituted adduct 4. Bromination of 4 with NBS, followed by debromofluorination with Mg, provided 2,3-diaryl-1,1-difluoro-1,3-butadienes (6) in good yields.