1264749-67-8Relevant articles and documents
Sequential protocol for C(sp)–H carboxylation with CO2: KOtBu-catalyzed C(sp)–H silylation and KOtBu-mediated carboxylation
Yu, Bo,Yang, Peng,Gao, Xiang,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Liu, Zhimin
, p. 449 - 456 (2018)
CO2 incorporation into C–H bonds is an important and interesting topic. Herein a sequential protocol for C(sp)–H carboxylation by employing a metal-free C–H activation/catalytic silylation reaction in conjunction with KOtBu-mediated carboxylation with CO2 was established, in which KOtBu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO2. Importantly, the carboxylation further promotes the silylation, which makes the whole reaction proceed very rapidly. Moreover, this methodology is simple and scalable, which is characterized by short reaction time, wide substrate scope, excellent functional-group tolerance and mild reaction conditions, affording a range of corresponding propiolic acid products in excellent yields in most cases. In addition, it also allows for a convenient 13C-labeling through the use of 13CO2.
Rhodium(III)-catalysed cascade [3 + 2] annulation of: N -aryloxyacetamides with 3-(hetero)arylpropiolic acids: Synthesis of benzofuran-2(3 H)-ones
Pan, Jin-Long,Liu, Tuan-Qing,Chen, Chao,Li, Quan-Zhe,Jiang, Wei,Ding, Tong-Mei,Yan, Zhi-Qiang,Zhu, Guo-Dong
supporting information, p. 8589 - 8600 (2019/10/02)
Herein, a cascade [3 + 2] annulation of N-aryloxyacetamides with 3-(hetero)arylpropiolic acids affording benzofuran-2(3H)-ones via rhodium(iii)-catalyzed redox-neutral C-H functionalization/isomerization/lactonization using an internal oxidative directing group O-NHAc was achieved. This catalytic system provides a regio- and stereoselective approach to synthesize (Z)-3-(amino(aryl)methylene)benzofuran-2(3H)-ones with exclusive Z configuration selectivity, acceptable yields and good functional group tolerance. Preliminary investigations on ultraviolet-visible and fluorescence behaviors reveal that the annulation products may be applied as a promising fluorescent probe for sensing metal cations, especially for cerium (Ce3+).
Palladium-catalyzed sonogashira reaction for the synthesis of arylalkynecarboxylic acids from aryl bromides at low temperature
Park, Kyungho,You, Jung-Min,Jeon, Seungwon,Lee, Sunwoo
, p. 1973 - 1978 (2013/05/09)
A variety of aryl bromides were coupled with propiolic acid in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and catalyst Pd(PPh 3)4 to afford the corresponding arylalkynecarboxylic acids in good yields at low temperature. This method showed good tolerance toward functional groups such as alkoxy, ketone, ester, aldehyde, cyano, nitro, and hydroxy. Under these conditions, propiolic acid showed higher reactivity than any other compound containing terminal alkyne groups. According to the mechanistic studies, the key reaction step for the high reactivity of propiolic acid might be ligand exchange between the acetylide and bromide at palladium, and/or reductive elimination, but not the oxidative addition step. A variety of aryl bromides were coupled with propiolic acid in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and catalyst Pd(PPh3) 4 to afford the corresponding arylpropiolic acids in good yields at low temperature.