Hydrocarbon Structure and Chemistry: Alkynes

Carbogallation of alkynes using gallium tribromide and silyl ketene acetals and synthetic application to cross-coupling with aryl iodides.

Palladium-catalyzed carbonylative Sonogashira coupling between aryl triazenes and alkynes.

We developed a palladium-catalyzed carbonylative Sonogashira reaction with aryl triazenes and alkynes as substrates and methanesulfonic acid as the additive. A series of α,β-ynones were synthesized by this alternative procedure. Notably, bromides, iodides and hydroxyl groups could be well-tolerated under these reaction conditions.

Highly selective synthesis of tetra-substituted furans and cyclopropenes: copper(I)-catalyzed formal cycloadditions of internal aryl alkynes and diazoacetates.

A convenient Cu(I)-catalyzed cycloaddition of electron rich internal aryl alkynes and diazoacetates was discovered for the chemoselective and regioselective synthesis of tetra-substituted furans and cyclopropenes in moderate isolated yields (18-67%), and alkyne conversion (29-73%).

Ligand-, copper-, and amine-free sonogashira reaction of aryl iodides and bromides with terminal alkynes.

Conditions for an efficient ligand-, copper-, and amine-free palladium-catalyzed Sonogashira reaction of aryl iodides and bromides with terminal alkynes have been developed. Critical to the success of this new protocol is the use of tetrabutylammonium acetate as the base. Noteworthy features of this method are room-temperature conditions and the tolerance of a broad range of functional groups i...

Hydrocarbon Structure and Chemistry: Aromatics

Hydrocarbons are organic compounds consisting of C-C and C-H bonds. Carbon has a valence of four and thus requires four electrons or bonds to complete its octet in the neutral state. Hydrogen has a valence of one and thus requires a single electron or bond to complete its "duet" in the neutral state. Thus in hydrocarbons carbon can form neutral bonding arrangements by forming single bonds with ...