850567-54-3Relevant articles and documents
Synthesis of Alkenylboronates from N-Tosylhydrazones through Palladium-Catalyzed Carbene Migratory Insertion
Chang, Taiwei,Huo, Jingfeng,Lei, Ming,Ping, Yifan,Wang, Jianbo,Wang, Qianyue,Wang, Rui
supporting information, p. 9769 - 9780 (2021/07/19)
The palladium-catalyzed oxidative borylation reaction of N-tosylhydrazones has been developed. The reaction features mild conditions, broad substrate scope, and good functional group tolerance. It thus represents a highly efficient and practical method for the synthesis of di-, tri-, and tetrasubstituted alkenylboronates from readily available N-tosylhydrazones. One-pot Suzuki coupling and other transformations highlight the synthetic utility of the approach. DFT calculations have revealed that palladium-carbene formation and subsequent boryl migratory insertion are the key steps in the catalytic cycle. The high stereoselectivity observed in the formation of trisubstituted alkenylboronates has been explained by distortion-interaction analysis and NBO analysis.
Atroposelective Synthesis of Conjugated Diene-Based Axially Chiral Styrenes via Pd(II)-Catalyzed Thioether-Directed Alkenyl C-H Olefination
Jin, Liang,Zhang, Peng,Li, Ya,Yu, Xin,Shi, Bing-Feng
, p. 12335 - 12344 (2021/08/24)
The efficient stereoselective synthesis of conjugated dienes, especially those with axial chirality, remains a great challenge. Herein, we report the highly atroposelective synthesis of axially chiral styrenes with a conjugated 1,3-diene scaffold via a Pd(II)-catalyzed thioether-directed alkenyl C-H olefination strategy. This strategy features easy operation, mild reaction conditions, high functional group tolerance (69 examples), complete Z-selectivity, and excellent enantioselectivities (up to 99% ee). Notably, the highly enantioselective synthesis of atropisomers with two stereogenic axes were also achieved using this strategy (up to 99% ee and 97:3 dr). Moreover, the reaction could be scaled up, and the resulting axially chiral styrenes could be easily oxidized into chiral sulfoxide derivatives with high diastereoselectivities, which showed great promise as a new type of sulfur-olefin ligand.
Rhodium-catalysed diastereo- And enantioselective cyclopropanation of α-boryl styrenes
Sun, Xiao,Gu, Peiming,Qin, Jiao,Su, Yan
supporting information, p. 12379 - 12382 (2020/10/30)
A rhodium-catalyzed diastereo- and enantio-selective cyclopropanation of a-boryl styrenes with a-diazoarylacetates was established. Rh2(S-PTTL)4 (0.2 mol%) was found to be effective for the conversion, and 21 diastereopure cyclopropylboronates were prepared in high yields with excellent enantioselectivity (ee up to 99%).
