Reaction rate differences between organotrifluoroborates and boronic acids in BINOL-catalyzed conjugate addition to enones
作者:Bailey Brooks、Noemi Hiller、Jeremy A. May
DOI:10.1016/j.tetlet.2021.153412
日期:2021.10
has been successfully employed in combination with trifluoroborate reagents for novel organic transformations over the last decade. However, no experimental rate studies of these reactions have been reported. Herein we report Hammett plot analysis of the organocatalyzed enantioselective conjugateaddition of alkenyl, aryl, and heteroaryltrifluoroborate salts to chalcone derivatives with substitution
The imino‐Nazarov cyclization of the polysubstituted pentan‐1,4‐diene‐3‐imines was realized. To this aim, a one‐pot procedure involving reductive alkenyliminylation of α,β‐unsaturated secondary amides with potassium organotrifluoroborates, followed by acid‐catalyzed imino‐Nazarov cyclization of the polysubstituted pentan‐1,4‐diene‐3‐imine intermediates, was studied systematically. This mild, operationally
Relay Catalysis To Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
作者:Sasha Sundstrom、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.9b04584
日期:2020.2.21
Organocatalysis was shown to facilitate conjugate additions to vinylogousesters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline)
Brønsted Acid Catalyzed Homoconjugate Addition of Organotrifluoroborates to Arylated Cyclopropyl Ketones
作者:Truong N. Nguyen、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.6b01795
日期:2016.8.5
A novel and practical homoconjugate addition of alkenyl, alkynyl, heteroaryl, and aryl trifluoroborates to arylated cyclopropylketones to synthesize γ,γ-disubstituted ketones is reported. A preliminary mechanistic proposal involving ketone protonation, an intermediary carbocation, and intermolecular nucleophile addition has been made based on control studies.
Iron(II)-Catalyzed Trifluoromethylation of Potassium Vinyltrifluoroborates
作者:Andrew T. Parsons、Todd D. Senecal、Stephen L. Buchwald
DOI:10.1002/anie.201108267
日期:2012.3.19
2‐heteroarylvinyl‐substituted substrates with E/Z selectivities of more than 95:5. Experimental observations suggest that the reaction does not proceed through a transmetalation of the RBF3K species to the iron catalyst.
用CF 3交换BF 3 :标题反应在极其温和的反应条件下进行,并提供2-芳基乙烯基-和2-杂芳基乙烯基-取代的底物,其E / Z选择性大于95:5。实验观察表明,该反应不是通过 RBF 3 K 物质向铁催化剂的金属转移来进行的。