9003-49-0Relevant articles and documents
Acid- And base-switched palladium-catalyzed γ-C(sp3)-H alkylation and alkenylation of neopentylamine
Zhang, Jinquan,Zhang, Shuaizhong,Zou, Hongbin
supporting information, p. 3466 - 3471 (2021/05/31)
The functionalization of remote unactivated C(sp3)-H and the reaction selectivity are among the core pursuits for transition-metal catalytic system development. Herein, we report Pd-catalyzed γ-C(sp3)-H-selective alkylation and alkenylation with removable 7-azaindole as a directing group. Acid and base were found to be the decisive regulators for the selective alkylation and alkenylation, respectively, on the same single substrate under otherwise the same reaction conditions. Various acrylates were compatible for the formation of C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds. The alkenylation protocol could be further extended to acrylates with natural product units and α,β-unsaturated ketones. The preliminary synthetic manipulation of the alkylation and alkenylation products demonstrates the potential of this strategy for structurally diverse aliphatic chain extension and functionalization. Mechanistic experimental studies showed that the acidic and basic catalytic transformations shared the same six-membered dimer palladacycle.
Second-Generation meta-Phenolsulfonic Acid-Formaldehyde Resin as a Catalyst for Continuous-Flow Esterification
Hu, Hao,Ota, Hajime,Baek, Heeyoel,Shinohara, Kenta,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
supporting information, p. 160 - 163 (2020/01/02)
A second-generation m-phenolsulfonic acid-formaldehyde resin (PAFR II) catalyst was prepared by condensation polymerization of sodium m-phenolsulfonate and paraformaldehyde in an aqueous H2SO4 solution. This reusable, robust acid resin catalyst was improved in both catalytic activity and stability, maintaining the characteristics of the previous generation catalyst (p-phenolsulfonic acid-formaldehyde resin). PAFR II was applied in the batchwise and continuous-flow direct esterification without water removal and provided higher product yields in continuous-flow esterification than any other commercial ion-exchanged acid catalyst tested.
Palladium-catalyzed regioselective synthesis of B(4,5)-or B(4)-substituted: O-carboranes containing α,β-unsaturated carbonyls
Li, Jiaoyi,Lu, Jian,Tian, Song,Wang, Qian,Zhang, Chuyi,Zhang, Jianwei,Zhou, Ling
, p. 4723 - 4727 (2020/07/13)
With the help of a carboxylic acid directing group, Pd-catalyzed regioselective synthesis of B(4,5)-or B(4)-substituted o-carboranes containing α,β-unsaturated carbonyls has been reported. The-COOH, removed during the course of the reaction, is responsible for controlling the regioselectivity. The desired products could be obtained in moderate to good yields.
