Synthesis of Fluoro- and Perfluoroalkyl Arenes via Palladium-Catalyzed [4 + 2] Benzannulation Reaction

Abstract

An efficient entry into densely substituted fluorinated and perfluoroalkylated benzene derivatives via chemo- and regioselective Pd-catalyzed [4 + 2] cross-benzannulation is presented. The synthetic utility of these products for the synthesis of various aromatic and heteroaromatic compounds is also demonstrated. This strategy offers a viable and quite general alternative to existing fluorination and perfluoroalkylation methods for securing these valuable molecules.

Dual Roles of TBHP-Enabled Regioselective Hydroetherification of (Trifluoromethyl)alkenes with Boronic Acids: Access to α-Trifluoromethyl β-Aryloxy Tertiary Alcohols

“…All reactions were conducted in oven-dried Schlenk tubes. In the scope of substrates, all the used (trifluoromethyl)alkenes 1a-k, arylboronic acids 2a-r, and t-BuOOH (3) were known compounds, of which (trifluoromethyl)alkenes 1a-i, 11 1j, 11 and 1k 7 were synthesized according to the reported literature, arylboronic acids 2a-r, and t-BuOOH (3) were purchased and used directly.…”

Silver‐Catalyzed Double Hydrocarbonation of 2‐Trifluoromethyl‐1,3‐Conjugated Enynes with 1,3‐Dicarbonyl Compounds: Synthesis of Ring‐Trifluoromethylated Cyclopentene

“…2‐Trifluoromethyl‐1,3‐enynes are versatile synth‐ons in making various types of fluorinated functionlized carbocycles such as cyclopentane, benzene and naphthalene derivatives and fluorinated heterocycles such as pyrrole, cyclic nitrone, isoxazole, 4 H ‐pyran, 2‐pyrroline, pyrrolidine and tetrahydro‐pyridine via transition metal catalyzed or simple base mediated cascade reactions . The synthetic application of 2‐trifluoromethyl‐1,3‐enynes has been thoroughly investigated by several research groups including Trost, Gevorgyan, Zhang, Jeong, and our group…”

Thioether-functionalized trifluoromethyl-alkynes, 1,3-dienes and allenes: divergent synthesis from reaction of 2-trifluoromethyl-1,3-conjugated enynes with sulfur nucleophiles

“…They could act as four- or two- carbon components in palladium catalyzed intermolecular formal [4 + 2] or [3 + 2] cycloaddition reactions for trifluoromethyl benzenes or exomethylene cyclopentane derivatives synthesis ( Scheme 1a ). 13 They also could serve as novel electrophiles to react with bisnucleophiles such as hydroxylamine, primary amine, aminomalonate and 1,3-dicarbonyl compounds for various fluorinated heterocycles synthesis such as pyrrole, N -hydroxypyrrole, isoxazole, cyclic nitrone, pyrroline, pyrrolidine and fluorinated carboncycles synthesis such as cyclopentene derivatives, etc. in transition metal catalysed or simple base mediated cascade reactions ( Scheme 1b ).…”