A Noncoordinating Acid–Base Catalyst for the Mild and Nonreversible <i>tert</i>-Butylation of Alcohols and Phenols
作者:Keith R. Fandrick、Nitinchandra D. Patel、Suttipol Radomkit、Arindom Chatterjee、Stefan Braith、Daniel R. Fandrick、Carl A. Busacca、Chris H. Senanayake
DOI:10.1021/acs.joc.1c00193
日期:2021.3.19
A mild and nonreversible tert-butylation of alcohols and phenols can be achieved in high yields using the noncoordinating acid–base catalyst [bis(trifluoromethane)sulfonimide and 2,6-lutidine] with a tert-butylation reagent, tert-butyl 2,2,2-trichloroacetimidate. This method allows the use of substrates containing acid sensitive groups such as ketal, Boc, and boronate esters.
Cetyltrimethylammonium Bromide as an Efficient Catalyst for Regioselective Bromination of Alkoxy Naphthalenes with Trimethyl Benzyl Ammonium Tribromide: Synthetic and Kinetic Approach
作者:K. Rajendar Reddy、K. C. Rajanna、K. Uppalaiah、S. Ramgopal
DOI:10.1002/kin.20821
日期:2014.1
Bromination of 2‐alkoxynaphthalene (2‐ANP) and its derivatives with trimethylbenzylammonium tribromide (TMBATB) did not proceed smoothly even under reflux conditions. But the addition of microconcentrations of cetyltrimethyl ammonium bromide (CTAB) to the reaction afforded dramatic rate accelerations as well as good‐to‐excellent yield of the products ranging from 70% to 90%. Reactions underwent regioselective
High-Yielding Palladium-Catalyzed Intramolecular Alkane Arylation: Reaction Development and Mechanistic Studies
作者:Marc Lafrance、Serge I. Gorelsky、Keith Fagnou
DOI:10.1021/ja076588s
日期:2007.11.28
Palladium-catalyzed alkane arylation reactions with aryl halides are described for the preparation of 2,2-dialkyl-dihydrobenzofuran substrates. These reactions occur in excellent yield and very high selectivity for the formation of one sole product arising from a reaction at nearby methyl groups. Mechanistic and computational studies point to the involvement of a concerted, inner-sphere palladation-deprotonation pathway that is enabled by the presence of three-center agostic interactions at the transition state. This mechanism accurately predicts the experimentally observed kinetic isotope effect as well as the site selectivity and should be useful in the design of new reactions and catalysts.