- NBS-mediated synthesis of β-keto sulfones from benzyl alcohols and sodium arenesulfinates
-
An efficient synthetic route towards the synthesis of β-keto sulfones has been developed from secondary benzyl alcohols using N-bromosuccinimide (NBS). The present protocol utilizes NBS as oxidant as well as brominating agent, readily accessible benzyl alcohols and sodium arenesulfinates as the sulfonylating reagent under mild conditions. The control experiments revealed that the reaction proceeds via oxidation of alcohol to ketone, α-bromination of ketone and nucleophilic substitution by sodium arenesulfinate. Furthermore, the efficiency of the methodology was tested with a gram scale reaction and also shown the synthetic utility.
- Muneeswara, Madithedu,Sundaravelu, Nallappan,Sekar, Govindasamy
-
p. 3479 - 3484
(2019/05/21)
-
- Enantioselective and Diastereoselective Construction of Chiral Amino Alcohols by Iridium-f-Amphox-Catalyzed Asymmetric Hydrogenation via Dynamic Kinetic Resolution
-
The iridium-f-amphox-catalyzed asymmetric hydrogenation of racemic α-amino β-unfunctionalized ketones proceeds via a DKR (dynamic kinetic resolution) process for the construction of various chiral N,N-disubstituted α-amino β-unfunctionalized alcohols in quantitative yields with excellent enantioselectivities and diastereoselectivities (all products >99% ee and >99:1 dr, TON up to 100 000). Importantly, this catalytic asymmetric hydrogenation with a DKR process provided a highly efficient and powerful synthetic strategy for the preparation of key chiral intermediates of the preclinical antitumor agent (S,S)-R116010.
- Wu, Weilong,You, Cai,Yin, Congcong,Liu, Yuanhua,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 2548 - 2551
(2017/05/24)
-
- Diminished reactivity of ortho-substituted phenacyl bromides toward nucleophilic displacement
-
A systematic increase of substitution rates by tert-butylamine on α-bromopropiophenones is observed with meta or para substituents with increasing electron-withdrawing ability (k x 103 L M-1 min-1 = 12.7 (p-CH3), 15.7 (o-F), 20.5 (H), 20.0 (p-Cl), 23.6 (m-Cl), 27.3 (p-CF3)). Within an ortho-substituted series, the reactivities decrease (k x 103 L M-1 min-1 = 7.64 (o-OCH3), 5.31 (o-CH3), 2.85 (o-Cl), 2.40 (o-CF3)). Ortho-substitution results occur from rotational barrier effects and an Aδσ + Bδσ + repulsion. The major bonding contribution between reaction and α-substituent centers (A-B) is only the σ bond. When π bonding is allowed between A and B (meta/para-substitution), delocalization and stabilization of the reacting center occurs.
- Kalendra, Diane M.,Sickles, Barry R.
-
p. 1594 - 1596
(2007/10/03)
-
- Arylheteroaryl inhibitors of farnesyl-protein transferase
-
The present invention is directed to compounds which inhibit famesyl-protein transferase (FTase) and the farnesylation of the oncogene protein Ras. The invention is further directed to chemotherapeutic compositions containing the compounds of this invention and methods for inhibiting famesyl-protein transferase and the famesyl of the oncogene protein Ras.
- -
-
-
- Pyrrole derivatives and medicinal composition
-
The invention relates to a pharmaceutical composition comprising a pyrrole derivative of the following formula [1] or a pharmaceutically acceptable salt thereof, or a solvate of either of them, as an active ingredient. STR1 (wherein R1 represents hydrogen or alkoxycar91 bonylamino, R2 represents alkyl, aryl which may be substituted, aromatic heterocyclyl which may be substituted, unsubstituted amino, monoalkylamino, dialkylamino, or cyclic amino which may be substituted; R3 represents cyano or carbamoyl; R4 represents hydrogen or alkyl; E represents alkylene; q is equal to 0 or 1, A represents methyl, aryl which may be substituted, or aromatic heterocyclyl which may be substituted). The pharmaceutical composition of the invention is effective for the treatment of pollakiuria or urinary incontinence.
- -
-
-
- Therapeutically useful 1-phenyl-2-piperidinoalkanol derivatives
-
Compounds of the formula: STR1 wherein R1 is hydrogen, halogen, trifluoromethyl, alkyl, hydroxyl, alkyoxy, benzyloxy, alkanoyloxy, or benzoyloxy, or when R2 is hydroxyl or methoxy in the 4-position and R3 is hydrogen, R1 may also represent hydroxymethyl carbamoyl or alkoxycarbonyl, R2 is hydrogen, halogen, alkyl, hydroxyl, or alkoxy, R3 is hydrogen or alkyl, R4 is alkyl (in which case the compounds are (±)-erythro) or when R3 represents hydrogen, R4 may also be hydrogen, and R5 is hydrogen, halogen, alkyl, alkoxy, or three methoxy groups in the 3-, 4- and 5-positions and pharmaceutically acceptable acid addition salts thereof, with the exclusion of compounds wherein: (a) one of R1 and R2 is in the 4-position and is hydroxyl, alkoxy or benzyloxy, the other is in the 3-position and is hydrogen, hydroxyl, alkoxy or benzyloxy, and R3 and R5 are hydrogen and wherein: (b) R1 is in the 4-position and is halogen, R4 is methyl and R2, R3 and R5 are hydrogen, are useful as medicaments.
- -
-
-