A new method for cross-coupling reaction of alkyl tosylates and bromides with Grignardreagents has been developed by the use of Pd(acac)2 or PdCl2 as the catalyst. Addition of 1,3-butadiene is essential to afford good yields of coupling products. This reaction proceeds efficiently at room temperature using primary and secondary alkyl and aryl Grignardreagents.
Titanocene-Catalyzed Carbosilylation of Alkenes and Dienes Using Alkyl Halides and Chlorosilanes
作者:Shinsuke Nii、Jun Terao、Nobuaki Kambe
DOI:10.1021/jo000483p
日期:2000.8.1
A new method for regioselective carbosilylation of alkenes and dienes has been developed by the use of a titanocene catalyst. This reaction proceeds efficiently at 0 degrees C in THF in the presence of Grignardreagents by the combined use of alkyl halides (R'-X, X = Br or Cl) and chlorotrialkylsilanes (R3''Si-Cl) as the alkylating and silylating reagents, respectively. Terminal alkenes having aryl
A Photoenzyme for Challenging Lactam Radical Cyclizations
作者:Todd K. Hyster、Bryce T. Nicholls、Tianzhang Qiao
DOI:10.1055/s-0040-1719872
日期:2022.7
organic synthesis and have been applied to the synthesis of structurally complex molecules. N-Heterocyclic motifs can be prepared through the cyclization of α-haloamides; however, slowrotationaround the amide C–N bond results in preferential formation of an acyclic hydrodehalogenated product. Here, we compare four different methods for preparing γ-, δ-, ε-, and ζ-lactams via radical cyclization.
1,3,2‐Diazaphospholene‐Catalyzed Reductive Cyclizations of Organohalides**
作者:Johannes Klett、Łukasz Woźniak、Nicolai Cramer
DOI:10.1002/anie.202202306
日期:2022.7.25
1,3,2-diazaphospholenes hydrides (DAP-H) are shown as efficient catalysts for reductive radical cyclization of aryl and alkyl halides under irradiation with visible light. The pivotal DAP catalyst turnover was achieved by a DBU-assisted σ-bondmetathesis between the formed DAP halide and HBpin.
The oxidative Heckreaction is a well-known organic transformation. However, previous reactions have been limited by the need for sophisticated directing or auxiliary groups, reliance on bulk solvents, lack of catalyst recycling, and the formation of a mixture of isomeric products, thereby hindering its broader application. Herein, we present a novel approach utilizing the polymer-assisted grinding