Palladium(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with Vinyl Bromides and 1,1-Dibromoalkenes
作者:Huan Li、Zhikun Zhang、Xianghang Shangguan、Shan Huang、Jun Chen、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201407000
日期:2014.10.27
Palladium‐catalyzed cross‐coupling reactions of 1,1‐diboronates with vinylbromides and dibromoalkenes were found to afford 1,4‐dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1‐diboronates and allylboron intermediates generated in the initial coupling.
Direct Alkynylation of 3<i>H</i>-Imidazo[4,5-<i>b</i>]pyridines Using <i>gem</i>-Dibromoalkenes as Alkynes Source
作者:Jessy Aziz、Tom Baladi、Sandrine Piguel
DOI:10.1021/acs.joc.6b00406
日期:2016.5.20
C2 direct alkynylation of 3H-imidazo[4,5-b]pyridine derivatives is explored for the first time. Stable and readily available 1,1-dibromo-1-alkenes, electrophilic alkyne precursors, are used as coupling partners. The simple reaction conditions include an inexpensive copper catalyst (CuBr·SMe2 or Cu(OAc)2), a phosphine ligand (DPEphos) and a base (LiOtBu) in 1,4-dioxane at 120 °C. This C–H alkynylation
首次探索了3 H-咪唑并[4,5- b ]吡啶衍生物的C2直接炔基化。稳定且易于获得的1,1-二溴-1-烯烃(亲电炔前体)用作偶联伙伴。简单的反应条件包括:廉价的铜催化剂(CuBr·SMe 2或Cu(OAc)2),膦配体(DPEphos)和1,4-二恶烷中的碱(LiO t Bu)在120°C的条件下。该C-H炔基化方法显露是与各种上两个耦合伙伴取代的兼容:杂芳烃和宝石-dibromoalkenes。该协议可以直接合成各种2-炔基-3 H-咪唑并[4,5- b]吡啶,一种在药物设计中有价值的支架。
Benzocycloheptynedicobalt Complexes by Intramolecular Nicholas Reactions
作者:James R. Green、Yu Ding
DOI:10.1055/s-2004-837215
日期:——
Lewis acid mediated intramolecular Nicholas reactions of aryl (Z)-enyne propargyl acetate-Co2(CO)6 complexes 1 afford benzocycloheptenyne-Co2(CO)6 complexes 2 and their heterocyclic analogues.
A Tandem Oxidation Procedure for the Conversion of Alcohols into 1,1-Dibromoalkenes
作者:Richard J. Taylor、Steven A. Raw、Mark Reid、Estelle Roman
DOI:10.1055/s-2004-820027
日期:——
A practical and concise route to dibromoalkenes directly from activated alcohols in good to excellent yields using a new Tandem OxidationProcedure (TOP) is reported. We also describe the use of these dibromoalkenes as intermediates in a one-pot route to 4,5-dihydro-1H-imidazoles and in the synthesis of bromoalkynes through MTBD-induced elimination.
One-pot conversion of activated alcohols into 1,1-dibromoalkenes and terminal alkynes using tandem oxidation processes with manganese dioxide
作者:Ernesto Quesada、Steven A. Raw、Mark Reid、Estelle Roman、Richard J.K. Taylor
DOI:10.1016/j.tet.2005.12.077
日期:2006.7
Approaches to the preparation of C1-homologated dibromoalkenes and terminal alkynes from activated alcohols using one-pot tandem oxidation processes (TOPs) with manganesedioxide are outlined. The conversion of alcohols into dibromoalkenes is described using dibromomethyltriphenylphosphonium bromide and the formation of terminal alkynes was achieved via a sequential one-pot, two-step process utilising