Crystallographic Characterization of Difluoropropargyl Indium Bromide, a Reactive Fluoroorganometallic Reagent

Abstract

Elusive intermediate trapped: γ‐Substituted difluoropropargyl groups can stabilize an organoindium(III) complex. The resulting structure is the only known example of an indium atom bonded to a propargylic carbon atom (see picture; F blue, S yellow, C white, H green). Reactions with electrophiles produced a difluoroalkyne or ‐allene, depending on the type of electrophile.

Designer HF-Based Fluorination Reagent: Highly Regioselective Synthesis of Fluoroalkenes and gem-Difluoromethylene Compounds from Alkynes

“…gem -Difluoromethylene (CF 2 )-containing compounds are important building blocks and targets in organic synthesis. 7a , 17 In this regard, dihydrofluorination of an alkyne is a straightforward and atom-economical way to synthesize CF 2 -containing compounds 3 . Olah and co-workers reported a synthesis of difluorinated alkanes with limited scope and selectivity.…”

Isolation and Crystallographic Characterization of Allylindium Species Generated from Allyl Halide and Indium(0)

“…To stabilize and isolate the species, pyridine was added to the mixture as a coordinative ligand (1/In = 1:1). [5,6,10] The 1 H NMR spectrum showed that both species 2 and 3 were complexed by the ligand (see Supporting Information), but a solid was not obtained after the usual treatment. Next, the addition of 3,5-dibromopyridine (Br 2 py) gave complexed species of 2 and 3 at an integration ratio of 1:1.38 (= 2·L n /3·L n ) (Chart c).…”

“…(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) report the actual structures of reductively generated allylindium species [10] commonly used for indium-mediated Barbier-type allylation in a practical synthetic method. [3] …”

On the Nature of Organoindium Intermediates: the Formation of Readily Isolable Difluoropropargylindium Reagents and their Regioselectivity Towards Electrophilic Substitutions

“…Its structure was determined by single-crystal X-ray techniques. [17] The other physical properties (melting points and UV absorption) of the indium complexes were also examined (see Supporting Information). The indium complexes also exhibit very strong UV absorption, generally their l max are around 250-300 nm, and their e max are around 5000 dm 3 mol À1 cm À1 .…”