57782-99-7Relevant articles and documents
Metal-Free C-O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
Bering, Luis,Jeyakumar, Kirujan,Antonchick, Andrey P.
supporting information, p. 3911 - 3914 (2018/07/22)
A catalytic, metal-free intramolecular rearrangement of benzyl phenyl ethers using nitrosonium salt as a catalyst is described. The optimized reaction conditions enabled a catalytic and metal-free Friedel-Crafts alkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel-Crafts reaction.
Enantioselective biomimetic cyclization of isoprenoids using Lewis acid-assisted chiral Bronsted acids: Abnormal claisen rearrangements and successive cyclizations
Nakamura, Shingo,Ishihara, Kazuaki,Yamamoto, Hisashi
, p. 8131 - 8140 (2007/10/03)
Syntheses of polycyclic isoprenoids have been achieved by several groups; however, no general "biomimetic" method has yet been reported. In this paper we describe the biomimetic cyclization of simple isoprenoids to polycyclic isoprenoids using Lewis acid-assisted chiral Bronsted acids, "chiral LBAs". This is the first example of a proton-induced enantioselective ene cyclization in synthetic chemistry. Geranyl phenyl ethers, o-geranylphenols, and geranylacetone derivatives were directly cyclized at -78 °C in the presence of (R)-binaphthol derivatives and tin tetrachloride. During the cyclization, [1,3] abnormal Claisen rearrangement often took place. The enantioselectivities were up to 90% ee. Compounds bearing a farnesyl group could also be cyclized under the same conditions to give the natural products (-)-Ambrox and (-)-chromazonarol. These chiral LBAs recognize a trisubstituted terminal olefin enantiotopically and generate site-selective carbocations on the substrates. The absolute stereochemistry of the cyclization is discussed with model studies using DFT calculations on the B3LYP/LANL2DZ level.
Total synthesis of polyprenylhydroquinols and benzoquinones
Bouzbouz, Samir,Kirschleger, Bernard,Villieras, Jean
, p. 67 - 84 (2007/10/03)
The total synthesis of polyprenylhydroquinols and benzoquinones is described.First, two appropriate aromatic allyl carbonates (moieties with one and two prenyls) and two activated bifunctional terpenyl derivatives (moieties with two and three prenyls) were synthesized.These molecules were then reacted together using a highly regio- and stereoselective coupling with Pd(PPh3)4 as a catalyst.The synthesis was achieved by functional group elimination and formation of quinonic and hydroquinonic moieties. - Keywords: polyprenylbenzoquinol; polyprenylhydroquinone; allylcarbonate; ?-allyl palladium complex
Geiparvarin analogues. 3. Synthesis and cytostatic activity of 3(2H)- furanone and 4,5-dihydro-3(2H)-furanone congeners of geiparvarin, containing a geraniol-like fragment in the side chain
Baraldi,Manfredini,Simoni,Tabrizi,Balzarini,De Clercq
, p. 1877 - 1882 (2007/10/02)
Continuing our study on the structural features of geiparvarin (1), responsible for cytostatic activity, a series of 4,5-dihydro-3(2H)-furanones 10a-f and of 3(2H)-furanones 11a-f as well as 2'',3''-dihydrogeiparvarin (14) have been designed and synthesiz
