Recent Developments with Organogermanes: their Preparation and Application in Synthesis and Catalysis

Abstract

Within the sphere of traditional Pd0/PdII cross coupling reactions, organogermanes have been historically outperformed both in terms of scope and reactivity by more conventional transmetalating reagents. Subsequently, this class of compounds has been largely underutilized as a coupling partner in bond‐forming strategies. Most recent studies, however, have shown that alternative modes of activation of these notoriously robust building blocks transform organogermanes into the most reactive site of the molecule – capable of outcompeting other functional groups (such as boronic acids, esters and silanes) for both C–C and C–heteroatom bond formation. As a result, over the past few years, the literature has increasingly featured methodologies that explore the potential of organogermanes as chemoselective and orthogonal coupling partners. Herein we highlight some of these recent advances in the field of organogermane chemistry both with respect to their synthesis and applications in synthetic and catalytic transformations.

Orthogonal sp3‐Ge/B Bimetallic Modules: Enantioselective Construction and Enantiospecific Cross‐Coupling

“…Notably, the acquisition of enantioenriched sp 3 -Ge reagents for use in stereospecific cross-coupling represents a significant challenge in the field of organogermanium chemistry. [20] There- fore, we here report the successful realization of this concept using our developed alkyl Ge as the partner for boron reagents (Figure 1b).…”

The structures and reactivity of NHC-supported copper(i) triphenylgermyls

“…In recent years, however, organogermanium systems have received growing acclaim as useful, orthogonal transmetallation group in a large and growing swathe of cross coupling reactions. 24,25 Given the limited number of copper(I) triphenylgermyl complexes thus described, and their potential utility in installing increasingly synthetically useful germyl groups, we set out to explore the chemistry of the well-precedented NHC ligand class with these underexplored moieties. This investigation was particularly interesting and attractive in the context of the vast dissimilitude in reactivity between copper(I) silyls and stannyls.…”

Construction of Ge-Stereogenic Center by Desymmetric Carbene Insertion of Dihydrogermanes

“…And germananes containing Ge–H bonds also tend to form germanium free radicals. A variety of organogermanium compounds have been synthesized and applied in organic synthesis, − catalysis, drug discovery, , and material science. − However, the enantioselective synthesis of chiral Ge-stereogenic germanes remains a challenge, with only one example reported by Nozaki, via a rhodium-catalyzed enantioselective [2 + 2 + 2] cycloaddition (Figure b). Therefore, a general synthetic method to prepare chiral germanium-stereogenic compounds is highly desired for exploring their functions.…”