720681-64-1Relevant academic research and scientific papers
NH2-directed C-H alkenylation of 2-vinylanilines with vinylbenziodoxolones
Boelke, Andreas,Caspers, Lucien D.,Nachtsheim, Boris J.
, p. 5344 - 5347 (2017)
The first directing-group-mediated C-H alkenylation with alkenyl-λ3-iodanes as electrophilic alkene-transfer reagents has been developed. The application of free aromatic amines as challenging but synthetically valuable directing groups in combination with an IrIII catalyst enabled the synthesis of highly desirable 1, 3- dienes in excellent yields of up to 98% with high to perfect (Z, E) stereoselectivity. A broad substrate scope and further synthetic modifications are demonstrated.
Experimental and Computational Studies on Cp*CyRh(III)/KOPiv-Catalyzed Intramolecular Dehydrogenative Cross-Couplings for Building Eight-Membered Sultam/Lactam Frameworks
Li, Liping,Gao, Hui,Sun, Ming,Zhou, Zhi,Yi, Wei
, p. 5473 - 5478 (2020/07/14)
Described herein is an unusual Cp*CyRh(III)-catalyzed intramolecular site-specific aryl C-H annulation, a highly chemoselective protocol providing direct access to eight-membered sultams/lactams with broad substrate/functional group tolerance. Experimental and computational studies reveal that such a transformation involves a unique PivOH-assisted aryl C-H activation/alkene insertion/β-H elimination/hydrogen-transfer process involving the Rh(III)-hydride species as the active intermediate with the concomitant release of H2 as the major byproduct, thus enabling the developed Cp*CyRh(III) catalysis with redox-neutral and highly atom-economical features.
Pd-catalyzed regiodivergent synthesis of diverse oxindoles enabled by the versatile heck reaction of carbamoyl chlorides
Wu, Xianqing,Tang, Zaiquan,Zhang, Chengxi,Wang, Chenchen,Wu, Licheng,Qu, Jingping,Chen, Yifeng
, p. 3915 - 3921 (2020/06/08)
We report herein a miscellaneous oxindole synthesis bearing an all-carbon quaternary center, enabled by Pd-catalyzed intramolecular cyclization followed by multiple intermolecular Heck reactions of both easily accessible alkene-tethered carbamoyl chlorides and olefins. This protocol obviates the use of prefunctionalized olefinic reagents, exhibits excellent functional group tolerance, and features fascinating reactive versatility.
Efficient synthesis of SCF3-substituted tryptanthrins by a radical tandem cyclization
Guo, Jincheng,Hao, Yanan,Li, Gang,Li, Yongqiang,Liu, Yuxiu,Wang, Qingmin,Wang, Ziwen
supporting information, p. 1994 - 2001 (2020/03/23)
Herein, we report a new, efficient and atom-economical strategy for the synthesis of SCF3-substituted tryptanthrin derivatives. These previously unreported derivatives were obtained by means of a radical tandem cyclization. The reaction was triggered by addition of a SCF3 radical to a carbon-carbon double bond and involved the formation of a C(sp3)-SCF3 bond, a C(sp2)-C bond, and a C(sp2)-N bond. This method has mild conditions and a wide range of substrates which is particularly useful for the preparation of substituted indolquinazoline derivatives that widely exist in many natural products, but are not easy to obtain by conventional approaches.
Direct Electrophilic C?H Alkynylation of Unprotected 2-Vinylanilines
Caspers, Lucien D.,Finkbeiner, Peter,Nachtsheim, Boris J.
, p. 2748 - 2752 (2017/03/08)
Unprotected aromatic amines can be used as directing groups in metal-catalyzed C?H alkynylations of alkenes. By using low amounts of an IrIIIcatalyst in combination with alkynylbenziodoxolones as electrophilic alkyne-transfer reagents, highly desirable 1,3-enynes were isolated in excellent yields of up to 98 % with Z stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3-enynes render this new method an efficient approach for the synthesis of five- and six-membered heterocycles. Further derivatizations of the 1,3-enynes to highly substituted quinolines through AuI- and N-bromosuccinimide-mediated exo-dig cyclizations were demonstrated.
Br?nsted Acid-Catalyzed Synthesis of N-Arylindoles from 2-Vinylanilines and Quinones
Zhang, Han-Ming,Gao, Zhong-Hua,Yi, Liang,Ye, Song
supporting information, p. 2671 - 2674 (2016/10/11)
In the presence of a quinone, Br?nsted acid-catalyzed intramolecular C?N bond formation of o-vinylanilines by electrophilic cyclization was developed, giving the corresponding N-arylindoles in good to high yields. The reaction worked well for o-vinylanilines with terminal and internal C=C double bonds.
