Gold Redox Catalysis through Base‐Initiated Diazonium Decomposition toward Alkene, Alkyne, and Allene Activation
作者:Boliang Dong、Haihui Peng、Stephen E. Motika、Xiaodong Shi
DOI:10.1002/chem.201701970
日期:2017.8.16
The discovery of photoassisted diazonium activation toward gold(I) oxidation greatly extended the scope of goldredoxcatalysis by avoiding the use of a strongoxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert
通过避免使用强氧化剂,光辅助重氮盐向金(I)氧化活化的发现大大扩展了金氧化还原催化的范围。限制这种新型化学方法应用的一些实际问题是相对较低的效率(较长的反应时间和较低的转化率)和必须进行严格的反应条件控制(脱气和惰性反应环境)。在本文中,通过路易斯碱诱导的重氮活化已经开发出另一种无光条件。通过这种方法,将不活泼的Au I催化剂与Na 2 CO 3和重氮盐结合使用以生产Au III中间的。实现了对各种基质(包括炔烃,烯烃和丙二烯)的有效活化,然后快速进行了Au III还原消除,从而得到了具有良好收率或优异收率的C-C偶联产物。相对于以前报道的光活化方法,我们的方法通过更快的反应速率和更宽的反应范围提供了更高的效率和多功能性。在光引发条件下(<5%收率)不能活化的具有挑战性的底物,例如富电子/中性亚勒烯,可以被活化,随后以良好或优异的产率产生所需的偶联产物。
Iridium-Catalyzed Intramolecular Oxidative Cyclization of Alkenyl Amides and Alkenoic Acids
Published as part of the Special Topic Modern Cyclization Strategies in Synthesis Abstract An iridium/dppf complex efficiently catalyzed the oxidativecyclization of N-sulfonyl alkenyl amides and alkenoic acids. Electron-deficient alkenes were effective as sacrificial hydrogen acceptors. High selectivity of the oxidativecyclization over the competing addition reaction has been realized by the use
Cobalt-Catalyzed Cyclization of Unsaturated <i>N</i>-Acyl Sulfonamides: a Diverted Mukaiyama Hydration Reaction
作者:David M. Fischer、Moritz Balkenhohl、Erick M. Carreira
DOI:10.1021/jacsau.2c00186
日期:2022.5.23
The cycloisomerization of β-, γ-, and δ-unsaturated N-acyl sulfonamides to N-sulfonyl lactams and imidates is reported. This transformation is effected in the presence of a CoIII(salen) catalyst using t-BuOOH or air as the oxidant. The method shows good functional group tolerance (alkyl, aryl, heteroaryl, ether, N-Boc) and furnishes an underexplored class of cyclic building blocks. The strong solvent
报道了β-、γ-和δ-不饱和N-酰基磺酰胺环异构化为N-磺酰基内酰胺和亚胺酸酯。这种转变是在 Co III (salen) 催化剂的存在下使用t -BuOOH 或空气作为氧化剂进行的。该方法显示出良好的官能团耐受性(烷基、芳基、杂芳基、醚、N -Boc),并提供了一类尚未开发的环状结构单元。研究了转化的强溶剂依赖性,并强调了N-磺酰亚胺酯产品类的合成多功能性。
Photo‐ and Cobalt‐Catalyzed Synthesis of Heterocycles via Cycloisomerization of Unactivated Olefins
作者:Henry Lindner、Willi M. Amberg、Tristano Martini、David M. Fischer、Eléonore Moore、Erick M. Carreira
DOI:10.1002/anie.202319515
日期:2024.5.6
A general, intramolecular cycloisomerization of unactivated olefins with pendant N-, O-, and C- nucleophiles is reported. The reaction proceeds under mild conditions, yielding a number of different heterocycles including, but not limited to, pyrrolidines, piperidines, oxazolidinones, and lactones. Use of both a benzothiazinoquinoxaline as organophotocatalyst and a Co-salen catalyst obviates the need
报道了未活化烯烃与侧链N -、 O - 和C - 亲核试剂的一般分子内环异构化。该反应在温和条件下进行,产生许多不同的杂环,包括但不限于吡咯烷、哌啶、恶唑烷酮和内酯。使用苯并噻嗪喹喔啉作为有机光催化剂和Co-salen催化剂消除了对化学计量氧化剂或还原剂的需要。
Cobalt-Catalyzed Aerobic Aminocyclization of Unsaturated Amides for the Synthesis of Functionalized γ- and δ-Lactams
作者:Manuel Freis、Moritz Balkenhohl、David M. Fischer、Tony Georgiev、Roman C. Sarott、Erick M. Carreira