Ruthenium-Catalyzed Transfer Oxygenative Cyclization of α,ω-Diynes: Unprecedented [2 + 2 + 1] Route to Bicyclic Furans via Ruthenacyclopentatriene
摘要:
A novel oxygen-atom-transfer process enables the catalytic [2 + 2 + 1] synthesis of bicyclic furans from alpha,omega-diynes with DMSO. [CpRu(AN)(3)]PF6 catalyzed the transfer oxygenative cyclization of diynes with aryl terminal groups, while those of diynes with alkyl terminal groups were effectively promoted by the corresponding Cp* complex. A mechanism for bicyclic furan formation via a ruthenacyclopentatriene was proposed on the basis of both experimental and theoretical studies.
A Combined Transition-Metal-Catalyzed and Photopromoted Process: Synthesis of 2,3-Fused 4-Phenylnaphthalen-1-yl Carboxylates from 1,7-Diaryl-1,6-diynes
2,3‐Fused 4‐phenylnaphthalen‐1‐yl carboxylates were synthesized in a step‐ and atom‐economical manner using a ruthenium‐catalyzed hydrocarboxylative cyclization of 1,7‐diaryl‐1,6‐diynes and subsequent oxidative photocyclization. The scope of this novel two‐step process was demonstrated by the construction of diverse structures from substrates with various tethers and terminal aryl groups. Late‐stage
A convergent formal [4 + 2] cycloaddition of 1,6-diynes and benzyl azides: construction of spiro-polyheterocycles
作者:Ming Bao、Wei Lu、Han Su、Lihua Qiu、Xinfang Xu
DOI:10.1039/c8ob00735g
日期:——
A convergent formal [4 + 2] cycloaddition reaction for the construction of structurally appealing spiro-tetrahydroquinolines has been developed, in which, a one-pot reaction is established for the in situ generation of two reagents, a cyclic alkyne and an N-aryliminium ion, from the corresponding precursors in the presence of an Au-catalyst and Brønsted acid, respectively.
calculations [PCM (THF) M06L/SDD-6-311++G(d,p)//B3LYP/LanL2DZ-6-31G(d)] and control experiments. The (Z)-selectivity increased when the bulkiness of the diyne terminal substituents increased. Notably, the reaction of 1,6-diynes bearing tert-butyl terminal groups with various α,β-unsaturated aldehydes exclusively afforded (Z)-dienyl ketones even at 70 °C when a cationic ruthenium complex with a smaller η5-cyclopentadienyl
Cp*Co(III)-Catalyzed Regioselective Synthesis of Cyclopenta[<i>b</i>]carbazoles via Dual C(sp<sup>2</sup>)–H Functionalization of 1-(Pyridin-2-yl)-indoles with Diynes
作者:Qiuyun Li、Yanwei Wang、Bin Li、Baiquan Wang
DOI:10.1021/acs.orglett.8b03438
日期:2018.12.21
Cp*Co(III)-catalyzedsynthesis of cyclopenta[b]carbazoles from 1-(pyridin-2-yl)-indoles and diynes is developed. This reaction involves dual C–H activation of indoles and domino cyclizations with diynes and has excellent regioselectivity, high efficiency, a broad substrate scope, and tolerance for various functional groups. A series of cyclopenta[b]carbazole molecular scaffolds are obtained in good
开发了Cp * Co(III)催化的1-(吡啶-2-基)-吲哚和二炔合成环戊[ b ]咔唑的方法。该反应涉及吲哚的双重C–H活化和带有二炔的多米诺环化反应,具有出色的区域选择性,高效率,广泛的底物范围以及对各种官能团的耐受性。以良好或优异的产率获得了一系列环戊[ b ]咔唑分子支架。
Rhodium(III)-Catalyzed [2+2+2] Cyclotrimerization of Diynes with Maleic Anhydrides as Alkyne Equivalents
作者:Takanori Matsuda、Kentaro Suzuki
DOI:10.1002/ejoc.201500252
日期:2015.5
anhydrides function as syntheticequivalents of alkynes in a rhodium(III)-catalyzed reaction with 1,6-diynes to achieve a formal [2+2+2] cyclotrimerization. This approach is useful for reactions involving alkynes with low boiling points or severe ring strain. Hard-to-access [2+2+2] cycloadducts are available through this new cycloaddition strategy by employing easy-to-handle alkyne equivalents.