An efficient rhodium‐catalyzed asymmetrichydrogenation of challenging tetrasubstituted cyclic enamides has been developed, affording cyclic chiral amides with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). This novel methodology provides an efficient and concise synthetic route to chiral cycloalkylamines with two contiguous stereogenic centers. The potential utility
Palladium-catalyzed aryl halide carbonylation–intramolecular O-enolate acylation: efficient isocoumarin synthesis, including the synthesis of thunberginol A
作者:Andrew C. Tadd、Mark R. Fielding、Michael C. Willis
DOI:10.1039/b917839b
日期:——
Exposure of a series of α-(o-haloaryl)-substituted ketones to palladium-catalyzed carbonylation conditions leads to the formation of the corresponding isocoumarins. Balloon pressure of CO is sufficient to achieve high yielding reactions, and both cyclic and acyclic ketones are efficient substrates. The utility of the method is illustrated by a short synthesis of the natural product thunberginol A.
Palladium-Catalyzed Synthesis of Isocoumarins and Phthalides via <i>tert</i>-Butyl Isocyanide Insertion
作者:Xiang-Dong Fei、Zhi-Yuan Ge、Ting Tang、Yong-Ming Zhu、Shun-Jun Ji
DOI:10.1021/jo302004u
日期:2012.11.16
efficient strategy for the synthesis of isocoumarins and phthalides through a palladium(0)-catalyzed reaction incorporating tert-butyl isocyanide has been developed. This process, providing one of the simplest methods for the synthesis of this class of valuable lactones, involves two steps including cyclization reaction and simple acid hydrolysis. The methodology is tolerant of a wide range of substrates
novel nickel catalyst for the reaction of tert-butyl isocyanide insertion was discovered. In this approach, 1,2-bis(diphenylphosphino)ethane (L3) serves as an efficient ligand, thereby allowing the preparation of lactones from (o-bromophenyl)phenylethanone derivatives. It is noteworthy that this is the first example of nickel acting as a metal catalyst in the reactions of tert-butyl isocyanide insertion
Iron and Copper Salts in the Synthesis of Benzo[b]furans
作者:Julien Bonnamour、María Piedrafita、Carsten Bolm
DOI:10.1002/adsc.201000269
日期:——
Intramolecular CO bond forming reactions of aryl 2‐bromobenzyl ketones lead to benzo[b]furans. The cyclizations can be catalyzed by 10 mol% of iron trichloride (of 98% or of 99.995% purity) or sub‐mol% quantities of copper(II) chloride (of 99.995% purity).
芳基2-溴苄基酮的分子内CO键形成反应导致苯并[ b ]呋喃。10 mol%的三氯化铁(纯度为98%或99.995%)或亚摩尔%的氯化铜(II)(纯度为99.995%)可以催化环化反应。