- A highly practical approach to chiral homoallylic-homopropargylic amines via aza-Barbier reaction
-
The first access to chiral homoallylic-homopropargylic amine bearing two contiguous stereocenters has been well accomplished via zinc-promoted aza-Barbier reaction. N-tert-Butanesulfinyl ketimines are well-tolerated substrates, providing the tertiary amin
- Yuan, Bin-Hua,Zhang, Zhi-Cheng,Liu, Wen-Jie,Sun, Xing-Wen
-
p. 2147 - 2151
(2016/05/02)
-
- Asymmetric intramolecular cyclopropanation of diazo compounds with metallosalen complexes as catalyst: Structural tuning of salen ligand
-
Intramolecular cyclopropanation of alkenyl α-diazoacetates and alkenyl diazomethyl ketones was examined by using optically active (ON+)Ru(II)(salen) and Co(II)(salen) complexes as catalysts. For the cyclization of 2-alkenyl α-diazoacetates, Co(II)(salen) complexes 9 and 10 were found to be superior catalysts to the corresponding (ON+)Ru(II)(salen) complexes 4 and 5. On the other hand, (ON+)Ru(II)(salen) complex 2 was found to be the catalyst of choice for the cyclization of 3-alkenyl diazomethyl ketones, and complex 4 was found to be a good catalyst for the cyclization of (E)-4-alkenyl diazomethyl ketones. The present study demonstrates that metallosalen complexes, especially optically active (ON+)Ru(II)(salen) and Co(II)(salen) complexes, can serve as efficient catalysts for the cyclization of alkenyl diazocarbonyl compounds, if a suitable salen ligand is used as the chiral auxiliary.
- Saha, Biswajit,Uchida, Tatsuya,Katsuki, Tsutomu
-
p. 823 - 836
(2007/10/03)
-
- New compounds, their preparation and use
-
The present invention relates to compounds of formula (I) The compounds are useful in the treatment and/or prevention of conditions mediated by nuclear receptors, in particular the Peroxisome Proliferator-Activated Receptors (PPAR).
- -
-
-
- A stereoselective synthesis of (E)-1-halo-6,6-dimethyl-2-hepten-4-yne: A key intermediate for terbinafine
-
A study of the stereoselective halogenation of 6,6-dimethyl-1-hepten-4- yn-3-ol (1) using a series of halogenating agents is described. Of the many agents investigated, boron trichloride is the most successful reagent for stereoselective halogenation (E:Z=9:1(max)). The resulting (E)-1-halo-6,6- dimethyl-2-hepten-4-yne (2), a key intermediate for terbinafine, an antifungal agent, is obtained in good yield and stereoselectivity. Two structurally related enyne alcohols have been studied likewise and shown similar versatility. (C) 2000 Elsevier Science Ltd.
- Chou, Shan-Yen,Tseng, Chin-Lu,Chen, Shyh-Fong
-
p. 3895 - 3898
(2007/10/03)
-