Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor
نویسندگان
چکیده
The limitation of hydroxamate ester as a chiral Lewis acid coordination moiety was first shown in an intermolecular reaction involving a radical addition and sequential allylation processes. Next, the effect of hydroxamate ester was studied in the cascade addition-cyclization-trapping reaction of substrates with a carbon-carbon triple bond as a radical acceptor. When substrates with a methacryloyl moiety and a carbon-carbon triple bond as two polarity-different radical acceptors were employed, the cascade reaction proceeded effectively. A high level of enantioselectivity was also obtained by a proper combination of chiral Lewis acid and these substrates.
منابع مشابه
Chem. Pharm. Bull. 53(8) 995—1002 (2005)
ways for carbon–carbon bond formation in organic synthesis. In particular, radical-mediated cyclization has been developed as a potential method for preparing various types of cyclic compounds via intramolecular carbon–carbon bond-forming processes. We have recently developed a new efficient carbon–carbon bond-forming reaction based on sulfanyl, stannyl and alkyl radical addition-cyclization (C...
متن کاملTitanocene(III) chloride mediated radical-induced opening of monosubstituted epoxy acetates for the synthesis of primary allylic alcohols
The radical chemistry has become an inevitable tool to the organic chemists now a days for the formation of carbon-carbon bonds. Prolific use of this particular field of chemistry is well established and growing continuously for the synthesis of carbocyclic as well as heterocyclic natural products. High stereo-and regioselectivity and mildness of the radical technique unaffecting various sensit...
متن کاملMechanism of the Stereoselective α-Alkylation of Aldehydes Driven by the Photochemical Activity of Enamines
Herein we describe our efforts to elucidate the key mechanistic aspects of the previously reported enantioselective photochemical α-alkylation of aldehydes with electron-poor organic halides. The chemistry exploits the potential of chiral enamines, key organocatalytic intermediates in thermal asymmetric processes, to directly participate in the photoexcitation of substrates either by forming a ...
متن کامل[Development of carbon radical addition to imine derivatives].
This review summarizes the new carbon-carbon bond construction methods based on the radical reaction of imine derivatives. The intermolecular carbon radical addition to oxime ethers proceeded smoothly in the presence of BF3.OEt2. A high degree of stereocontrol in the reaction of oxime ethers was achieved to give amino acid derivatives with excellent diastereoselectivities. The radical reaction ...
متن کاملGeneration of radical species by one electron oxidation with metallic compounds for the construction of carbon skeletons
By oxidation of P-keto acids, cyclopropanols, and acyl chromate complexes with tris(2-pyridinecarboxylato)manganese(III) (Mn(pic)g), a-keto, p-keto, and alkyl radicals are generated respectively, which react with olefinic compounds to afford intermolecular addition products in good yield. The cation radicals can be generated from a-stannylalkyl sulfides, (1 -stannylalkyl)amino compounds, and a-...
متن کامل