Gold(I)‐Catalyzed Synthesis of Indenes and Cyclopentadienes: Access to (±)‐Laurokamurene B and the Skeletons of the Cycloaurenones and Dysiherbols
نویسندگان
چکیده
The formal (3+2) cycloaddition between terminal allenes and aryl or styryl gold(I) carbenes generated by a retro-Buchner reaction of 7-substituted 1,3,5-cycloheptatrienes led to indenes and cyclopentadienes, respectively. These cycloaddition processes have been applied to the construction of the carbon skeleton of the cycloaurenones and the dysiherbols as well as to the total synthesis of (±)-laurokamurene B.
منابع مشابه
Gold(I)-catalyzed cycloisomerizations and alkoxycyclizations of ortho-(alkynyl)styrenes.
Indenes and related polycyclic structures have been efficiently synthesized by gold(I)-catalyzed cycloisomerizations of appropriate ortho-(alkynyl)styrenes. Disubstitution at the terminal position of the olefin was demonstrated to be essential to obtain products originating from a formal 5-endo-dig cyclization. Interestingly, a complete switch in the selectivity of the cyclization of o-(alkynyl...
متن کاملGold(I)-catalyzed synthesis of functionalized cyclopentadienes.
mechanistic pathways: a concerted rearrangement (path a) involving direct addition of the olefin on the epoxide or a stepwise mechanism (path b) through a Nazarov cyclization of an oxypentadienyl cation (2, X=O ). The regioselectivity of the cyclization is dictated by donation of the oxyanion into the resulting cation leading to the formation of a ketone. Recently, stabilization of developing p...
متن کاملA combined mechanistic and computational study of the gold(I)-catalyzed formation of substituted indenes.
Substituted indenes can be prepared after a sequence [1,3] O-acyl shift-hydroarylation-[1,3] O-acyl shift. Each step is catalyzed by a cationic NHC-Gold(I) species generated in situ after reaction between [(IPr)AuOH] and HBF(4)·OEt(2). This interesting silver-free way is fully supported by a computational study justifying the formation of each intermediate.
متن کاملSynthesis and Functionalization of Gold Nanoparticles by Using of Poly Functional Amino Acids
Synthesis and characterization of two functionalized gold nanoparticles by using of two poly functional amino acids (L-Arginine and L-Aspartic acid) are reported. The gold nanoparticles were reduced by sodium citrate and functionalized with L-Arginine at the pH of 7 and 11 and L-Aspartic acid at the pH of 7. Transmission electron microscopy, UV-Vis spectroscopy, dynamic light scattering, zeta p...
متن کامل