863970-06-3Relevant academic research and scientific papers
Rh(III)-Catalyzed meta-C-H Alkenylation with Alkynes
Xu, Hua-Jin,Kang, Yan-Shang,Shi, Hang,Zhang, Ping,Chen, You-Ke,Zhang, Bing,Liu, Zhi-Qiang,Zhao, Jing,Sun, Wei-Yin,Yu, Jin-Quan,Lu, Yi
, p. 76 - 79 (2019)
Rh(III)-catalyzed meta-C-H functionalization reactions are still rare. Herein, we report the first example of Rh(III)-catalyzed meta-C-H alkenylation with disubstituted alkynes directed by a U-shaped nitrile template. Exclusive regio-selectivity has been achieved using unsymmetrical aryl and alkyl-disubstituted alkynes to afford synthetically valuable trisubstituted olefins. Propargyl alcohols are also compatible, affording complex allylic alcohols. Notably, transition metal-catalyzed meta-alkenylation with alkynes has not been successful with Pd catalysts.
Asymmetric Propargylic Radical Cyanation Enabled by Dual Organophotoredox and Copper Catalysis
Lu, Fu-Dong,Liu, Dan,Zhu, Lei,Lu, Liang-Qiu,Yang, Qian,Zhou, Quan-Quan,Wei, Yi,Lan, Yu,Xiao, Wen-Jing
supporting information, p. 6167 - 6172 (2019/04/17)
The first asymmetric propargylic radical cyanation was realized through a dual photoredox and copper catalysis. An organic photocatalyst serves to both generate propargyl radicals and oxidize Cu(I) species to Cu(II) species. A chiral Cu complex functions as an efficient organometallic catalyst to resemble the propargyl radical and cyanide in an enantio-controlled manner. Thus, a diverse range of optically active propargyl cyanides were produced with high reaction efficiency and enantioselectivities (28 examples, 57-97% yields and 83-98% ee). Moreover, mechanistic investigations including experiments and density functional theory calculations were performed to illustrate on the reaction pathway and stereochemical results.
Titanium-Promoted Cross-Coupling for the Selective Synthesis of Polysubstituted, Conjugated Amides
Chenniappan, Vinoth Kumar,Rahaim, Ronald J.
supporting information, p. 5090 - 5093 (2016/10/14)
α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the E isomer with good chemoselectivity and regioselectivity (>95/5), for unsymmetrical internal alkynes that contain a steric bias. The reactive titanacyclopentene intermediate formed from the coupling of the alkyne and isocyanate was additionally reacted with various electrophiles to access tetrasubstituted enamides.
PtI2-Catalyzed tandem 3,3-rearrangement/Nazarov reaction of arylpropargylic esters: Synthesis of indanone derivatives
Zheng, Huaiji,Xie, Xingang,Yang, Juan,Zhao, Changgui,Jing, Peng,Fang, Bowen,She, Xuegong
experimental part, p. 7755 - 7762 (2011/12/03)
An efficient PtI2-catalyzed tandem reaction of arylpropargylic esters, involving 3,3-rearrangement and Nazarov reaction, has been developed to produce 3-substituted and 3,3-disubstituted indanone derivatives. This approach provided a pathway to the synthesis of indanone skeletons in natural products.
Cationic rhodium(I)/BINAP complex-catalyzed isomerization of secondary propargylic alcohols to α,β-enones
Tanaka, Ken,Shoji, Takeaki
, p. 3561 - 3563 (2007/10/03)
(Chemical Equation Presented) We have developed a cationic rhodium(I)/BINAP complex-catalyzed isomerization of secondary propargylic alcohols to α,β-enones. The asymmetric variant of this reaction, a kinetic resolution of secondary propargylic alcohols, was also developed with good selectivity. The mechanistic study revealed that the isomerization proceeds through intramolecular 1,3- and 1,2-hydrogen migration pathways.
