我们报告了烷基锌试剂与 α,α-二氟溴乙酰胺的镍催化羰基化交叉偶联反应,以中等至良好的产率获得 α,α,-二氟-β-酮酰胺。与其他涉及钯催化剂的报道不同,该反应由稳定的镍 (II) 钳络合物催化。羰基化反应在双室系统 (COware) 中进行,其中一氧化碳 (CO)从固体前体 SilaCOgen非原位生成,然后在相邻室中消耗。该反应使用接近化学计量的 CO 在低温下进行。可以毫不费力地获得同位素标记的产品,如使用13 C 标记的 SilaCOgen 所证明的那样。
Novel 19-nor-steroids of the formula ##STR1## wherein the A and B rings have a structure selected from the group consisting of ##STR2## having hormonal properties and their preparation and intermediates.
of unactivated alkyl chlorides with tethered alkenes. The cleavage of strong C(sp3)−Cl bonds is mediated by a highly nucleophilic low‐valent cobalt or nickel intermediate generated by visible‐light photoredox reduction employing a copper photosensitizer. The high basicity and multidentate nature of the ligands are key to obtaining efficient metal catalysts for the functionalization of unactivated alkyl
Transition-Metal-Free Borylation of Alkyl Iodides via a Radical Mechanism
作者:Qianyi Liu、Junting Hong、Beiqi Sun、Guangcan Bai、Feng Li、Guoquan Liu、Yang Yang、Fanyang Mo
DOI:10.1021/acs.orglett.9b01951
日期:2019.9.6
transition-metal-free borylation of alkyliodides. This method uses commercially available diboron reagents as the boron source and exhibits excellent functional group compatibility. Furthermore, a diverse range of primary and secondaryalkyliodides could be effectively transformed to the corresponding alkylboronates in excellent yield. Mechanisticinvestigations suggest that this borylation reaction
Nickel-catalyzed cross-coupling of unactivated alkyl halides and tosylate carrying a functional group with alkyl and phenyl Grignard reagents
作者:Surya Prakash Singh、Jun Terao、Nobuaki Kambe
DOI:10.1016/j.tetlet.2009.07.094
日期:2009.10
primary and secondaryalkylGrignardreagents undergo cross-coupling with alkyl bromides, iodide, and tosylate carrying a functional group such as amide, ester, and ketone at 0 °C in THF. The present procedure provides a simple, convenient, and practical method for construction of carbon chains in the presence of various functional groups. PhMgBr also gave the corresponding coupling product in a moderate
The Palladium-Catalyzed Anti-Markovnikov Hydroalkylation of Allylic Alcohol Derivatives
作者:Ryan J. DeLuca、Matthew S. Sigman
DOI:10.1021/ol303129p
日期:2013.1.4
A palladium-catalyzed hydroalkylation reaction of protected allylicalcohols using alkylzinc bromide reagents is reported. This account includes numerous allylic, homoallylic, and bishomoallylic alcoholderivatives, all with a uniform selectivity of >20:1 for the anti-Markovnikov product. The reaction features the ability to deliver enantiomerically enriched alcohols in unfunctionalized regions, which