Radical Borylation/Cyclization Cascade of 1,6-Enynes for the Synthesis of Boron-Handled Hetero- and Carbocycles
作者:Shi-Chao Ren、Feng-Lian Zhang、Jing Qi、Yun-Shuai Huang、Ai-Qing Xu、Hong-Yi Yan、Yi-Feng Wang
DOI:10.1021/jacs.7b01889
日期:2017.5.3
construct boron-handled cyclic molecules was developed based on a radical borylation/cyclization cascade of 1,6-enynes. The process was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to an alkene or alkyne, followed by ring closure to afford boron-substituted cyclic skeletons. Further molecular transformations of the cyclic products to synthetically
Radical Deoxygenation of Xanthates and Related Functional Groups with New Minimalist N-Heterocyclic Carbene Boranes
作者:Shau-Hua Ueng、Louis Fensterbank、Emmanuel Lacôte、Max Malacria、Dennis P. Curran
DOI:10.1021/ol101015m
日期:2010.7.2
Minimalist N-heterocycliccarbeneboranes 1,3-dimethylimidazol-2-ylideneborane and 2,4-dimethyl-1,2,4-triazol-3-ylideneborane are readily available and have low molecular weights. They exhibit superior performance to first-generation NHC−boranes, providing improved yields in reductions of xanthates and related functional groups.
Regioselective radical hydroboration of electron-deficient alkenes: synthesis of α-boryl functionalized molecules
作者:Yun-Shuai Huang、Jie Wang、Wan-Xin Zheng、Feng-Lian Zhang、You-Jie Yu、Min Zheng、Xiaoguo Zhou、Yi-Feng Wang
DOI:10.1039/c9cc06506g
日期:——
various electron-deficient alkenes is achieved by the employment of an NHC–boryl radical. A range of α-borylated nitriles, trifluoromethyl molecules, phosphonates, sulfones, and gem-diboron compounds have been prepared from readily available startingmaterials. Further synthetic applications of these products are also demonstrated.
Hydroboration of Arynes with N-Heterocyclic Carbene Boranes
作者:Tsuyoshi Taniguchi、Dennis P. Curran
DOI:10.1002/anie.201408345
日期:2014.11.24
Arynes were generated in situ from ortho‐silyl aryl triflates and fluoride ions in the presence of stable N‐heterocyclic carbeneboranes (NHCBH3). Spontaneous hydroboration ensued to provide stable B‐aryl‐substituted NHC‐boranes (NHCBH2Ar). The reaction shows good scope in terms of both the NHC‐borane and aryne components and provides direct access to mono‐ and disubstituted NHC‐boranes. The formation
Borylative Radical Cyclizations of Benzo[3,4]cyclodec‐3‐ene‐1,5‐diynes and N‐Heterocyclic Carbene‐Boranes
作者:Takashi Watanabe、Daisuke Hirose、Dennis P. Curran、Tsuyoshi Taniguchi
DOI:10.1002/chem.201700689
日期:2017.4.24
Borylative radical cyclization of benzo[3,4]cyclodec‐3‐ene‐1,5‐diynes to provide 5‐borylated 6,7,8,9‐tetrahydrobenzo[a]azulenes has been developed. The experimental results suggest that the reaction proceeds by a radical chain mechanism, in which di‐tert‐butyl hyponitrite (TBHN) works as a good radical initiator to form borylradicals from N‐heterocyclic carbene–boranes (NHC‐boranes). The present reaction
已开发出苯并[3,4] cyclodec-3-烯-1,5-二炔的硼酸自由基环化反应,以提供5硼酸化的6,7,8,9-四氢苯并[ a ] azulenes。实验结果表明,反应是通过自由基链机理进行的,其中二叔丁基亚硝酸盐(TBHN)作为良好的自由基引发剂,可从N杂环卡宾-硼烷(NHC-硼烷)形成硼自由基。本反应是罕见的模型,其说明了向炔烃中加硼基。