An efficient tertiary alkylation reaction of olefins with 1,3-dicarbonyl compounds was developed by virtue of copper catalyst without the use of expensive ligands or additives. In contrast to alkyl Heck-type reaction, alkylhalide is not required. Notably, by varying the nitrogen and air atmosphere, the reaction selectively produces alkylation and alkylation–oxygenation products, respectively. Initial
<i>trans</i>-Directing Ability of the Amide Group: Enabling the Enantiocontrol in the Synthesis of 1,1-Dicarboxy Cyclopropanes. Reaction Development, Scope, and Synthetic Applications
作者:David Marcoux、Sébastien R. Goudreau、André B. Charette
DOI:10.1021/jo902066y
日期:2009.12.4
enantioselective formation of 1,1-cyclopropane diesters via the metal-catalyzed cyclopropanation of olefins. The strategies envisioned to achieve such a goal are discussed as well as the results that led us to the discovery of the powerful trans-directingability of the amidegroup in Rh(II)-catalyzed cyclopropanation reactions. We show how this feature enables a solution for the stereoselective synthesis
Nickel-Catalyzed Markovnikov Transfer Hydrocyanation in the Absence of Lewis Acid
作者:Nils L. Frye、Anup Bhunia、Armido Studer
DOI:10.1021/acs.orglett.0c01454
日期:2020.6.5
Hydrocyanation in the absence of toxic HCN gas is highly desirable. Addressing that challenge, transition-metal-catalyzed transfer hydrocyanation using safe HCN precursors has been developed, but these reagents generally require a Lewis acid for activation, and the control of regioselectivity often remains problematic. In this Letter, a Ni-catalyzed highly Markovnikov-selective transfer hydrocyanation
acylfluoroalkylation of a variety of olefins in the presence of various commercially available aromatic aldehydes and fluoroalkyl reagents through N-heterocyclic carbeneorganocatalysis. With this protocol, over 120 examples of functionalized ketones with diverse fluorine substituents have been synthesized in up to 99 % yield with complete regioselectivity. The generality of this catalytic strategy was further
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.