已经开发了使用炔烃的铜催化分子内NH / CH环合反应。各种稠密官能化的杂环,如吡咯并[1,2- a ]吲哚,吲哚并[1,2 - c ]喹唑啉-2-酮,恶唑并[3,4- a ]吲哚和咪唑[1,5-由于苯胺部分,连接子部分和炔烃部分具有高度模块化的特征,因此以原子和分步经济的方式合成了α ]吲哚。通过简单地改变从二氧化剂叔将过氧化叔丁基(DTBP)转化为2,2,6,6-四甲基哌啶-1-氧基(TEMPO),该反应很容易转化为氨氧化途径,该途径从TEMPO夺取一个氧原子以生成5-芳酰基吡咯2个 机理实验表明,乙烯基自由基参与了该反应,而酰胺基自由基引发的自由基级联反应可能是造成这种转变的原因。
Rhodium-Catalyzed C–O Bond Alkynylation of Aryl Carbamates with Propargyl Alcohols
作者:Kosuke Yasui、Naoto Chatani、Mamoru Tobisu
DOI:10.1021/acs.orglett.8b00674
日期:2018.4.6
The rhodium-catalyzedalkynylation of aryl carbamates with propargyl alcohols is described. This methodology can provide aryl acetylenes from aryl carbamates via C–O bond activation. The use of propargyl alcohols as alkynylating agents allows the use of a variety of functional groups that are incompatible with organometallic nucleophiles. This reaction also serves to broaden the utility of a carbamate
Asymmetricconjugatealkynylation of α,β-unsaturated ketones with (triisopropylsilyl)ethynylsilanols giving β-alkynylketones took place in high yields with high enantioselectivity in the presence of chiral rhodium catalysts.
Oxidative alkynylation of acrylate esters with propargylic alcohols giving conjugated enyne esters was realized by use of a diene–rhodium catalyst. Propargylic alcohols were found to be useful alkynylating reagents in the present reaction to produce alkynylrhodium species via carbon–carbon bond cleavage. An excess of the acrylate ester worked as a hydride acceptor to reproduce the active rhodium species
Rhodium(I)-Catalyzed Sequential C(sp)C(sp<sup>3</sup>) and C(sp<sup>3</sup>)C(sp<sup>3</sup>) Bond Formation through Migratory Carbene Insertion
作者:Ying Xia、Sheng Feng、Zhen Liu、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201503140
日期:2015.6.26
A RhI‐catalyzed three‐component reaction of tert‐propargyl alcohol, diazoester, and alkyl halide has been developed. This reaction can be considered as a carbene‐involving sequential alkyl and alkynyl coupling, in which C(sp)C(sp3) and C(sp3)C(sp3) bonds are built successively on the carbenic carbon atom. The RhI‐carbene migratory insertion of an alkynyl moiety and subsequent alkylation are proposed
We herein report a novel 1,5-palladium/hydrogen shift pattern between a vinyl and an acyl group, which provides a divergent access to substituted 5-membered-dihydrobenzofurans and indolines. Further studies unveiled a novel relayed decarbonylative Catellani-type reaction. Mechanistic investigations including DFT calculations have shed light on the reaction pathway.