Stereoselective Sulfinyl Aniline-Promoted Pd-Catalyzed C?H Arylation and Acetoxylation of Aliphatic Amides
Stereoselective functionalization of aliphatic C?H bonds presents a great challenge. Following this target, we disclose herein an original strategy towards direct arylation of aliphatic chains at ?-methylene position based on a use of amide-sulfoxide bicoordinating directing group. Although moderate to high chiral induction (up to 9:1 d.r.) is achieved, diastereomerically pure compounds may be afforded by simple separation of diastereomeric products by silica gel chromatography. Accordingly, this reaction allows preparation of a large scope of high-value scaffolds in synthetically useful yields while recyclable character of our chiral auxiliary brings an additional benefit. A potential of this methodology to build up original molecules by sequential diarylation and expedient (two step) synthesis of a biologically active compound are further disclosed. Finally a first example of stereoselective direct acetoxylation of aliphatic chains is reported.
Asymmetric syntheses and bio-evaluation of novel chiral esters derived from substituted tetrafluorobenzyl alcohol
A series of novel chiral esters derived from tetrafluorobenzyl alcohol were designed and prepared via asymmetric synthesis. The target molecules have been identified on the basis of analytical spectra data. All newly synthesized compounds have been screened their potential insecticidal activity against Plutella xylostella compared with those of fenvalerate and d-trans-phenothrin by standard method, and the respective pairs of enantiomers (3-B1-R/S, 3-C1-R/S, 3-D1-R/S) indicated significantly different activities.
Asymmetric syntheses and bio-evaluation of novel chiral esters derived from substituted tetrafluorobenzyl alcohol
A series of novel chiral esters derived from tetrafluorobenzyl alcohol were designed and prepared via asymmetric synthesis. The target molecules have been identified on the basis of analytical spectra data. All newly synthesized compounds have been screened their potential insecticidal activity against Plutella xylostella compared with those of fenvalerate and d-trans-phenothrin by standard method, and the respective pairs of enantiomers (3-B1-R/S, 3-C1-R/S, 3-D1-R/S) indicated significantly different activities.