Low‐Coordinate Germanium(II) Centers Within Distorted Axially Chiral Seven‐Membered Chelates: Stereo‐ and Enantioselective Cycloadditions

Abstract

Distorted germylene: A distorted seven‐membered N‐heterocyclic germylene, which has a germanium center of relatively high Lewis acidity, reacts with benzaldehyde to give (2+1+1) or (2+2+1) cycloadducts. The type of cycloadduct produced in the reaction is dependent on the ratio of substrates used. It is considered that the reactions involve stereoselective 1,3‐dipolar cycloadditions of an in situ generated carbonyl germaylide.

Redox‐Active N‐Heterocyclic Germylenes and Stannylenes with a Ferrocene‐1,1′‐diyl Backbone

“…104–107°) are much larger (by approximately 20°) than in the five‐membered ring N‐heterocyclic germylenes (ca. 83–88°), and also significantly larger (by approximately 10°) than in the six‐ and seven‐membered ring congeners (ca. 95–99°).…”

Stable N‐Heterocyclic Germylenes of the Type [Fe{(η5‐C5H4)NR}2Ge] and Their Oxidation Reactions with Sulfur, Selenium, and Diphenyl Diselenide

“…Although the chemistry of N‐heterocyclic germylenes has developed remarkably since these early days, it is still far away from the maturity that has been reached in the field of NHCs. For example, it has only been recently that applications of N‐heterocyclic germylenes and closely related Ge II compounds in materials science, organic synthesis, and catalysis have emerged …”

Recent advances in the chemistry of isolable carbene analogues with group 13–15 elements

“…Oxidative reactions are typically observed with oxidants such as I 2 , 261 O 2 , 244 and N 2 O, 262 while cycloaddition reactions can involve alkenes, alkyne 242 and aldehyde. 263 Beyond this classic reactivity, when coordinated with specific TMs, the NHM-TM complexes can serve as catalysts. 7 For example, benzannulated metallylenes featuring dual phosphino functional groups can lead to the synthesis of pincer-type germylenes, which show promise in catalytic applications.…”