Modular Approach to 9-Monosubstituted Fluorene Derivatives Using Mo(V) Reagents.

Oxidative coupling using molybdenum(V) reagents provides fast access to highly functionalized 9-monosubstituted fluorenes. This synthetic approach is highly modular, is high yielding, and tolerates a variety of labile moieties, e.g. amides or iodo groups. The established protocol leads to promising precursors for pharmacologically important analogues of melatonin.

Oxidative (Cross-)Coupling Reactions Mediated by C-H Activation of Thiophene Derivatives by Using Molybdenum(V) Reagents

Oxidative coupling by using molybdenum pentachloride provides fast and modular access to sophisticated thienoacenes in excellent yields. The coupling process can be accomplished with thiophene and benzothiophene derivatives and provides various complex skeletons such as spirocyclic compounds. In this approach, the first cross-coupling reactions with the use of MoCl5 were established and important motifs for semiconducting materials were synthesized.

ChemInform Abstract: Oxidative (Cross-)Coupling Reactions Mediated by C-H Activation of Thiophene Derivatives by Using Molybdenum(V) Reagents.

The use of MoCl5 renders possible the preparation of various synthetically important polycyclic thienoacenes.

ChemInform Abstract: Modular Approach to 9-Monosubstituted Fluorene Derivatives Using MoVReagents.

Modular Access to 9,9-Spirobifluorenes by Oxidative Coupling Using Molybdenum Pentachloride

The strong oxidizing agent molybdenum pentachloride was used for an efficient direct C–C bond formation of 9,9-diarylfluorenes to the corresponding 9,9-spirobifluorenes. Thus, a versatile method that is compatible with labile groups, such as iodo moieties, was established. By this approach important building blocks for light emitting polymers were synthesized in high yields.

Oxidative transformation of aryls using molybdenum pentachloride.

Molybdenum pentachloride combines a strong Lewis acid character with an unusually high oxidation potential creating a powerful reagent for oxidative transformations. Since the oxidative coupling reaction of aryls is induced at an extraordinarily high reaction rate, a variety of labile groups, e.g. iodo, tert-alkyl, etc., are tolerated on the aromatic core. Furthermore, the co-formed molybdenum salts can either be exploited for template effects to obtain uncommon geometries in a preferred manner, or redox-play starts after aqueous workup. Therefore MoCl(5) represents a unique and easily available reagent.

ChemInform Abstract: Modular Access to 9,9-Spirobifluorenes by Oxidative Coupling Using Molybdenum Pentachloride.

The reactions of diarylfluorenes and substrates (III) or (V) result in formation of spirobifluorenes and fluorene derivatives.

ChemInform Abstract: Oxidative Transformation of Aryls Using Molybdenum Pentachloride

Molybdenum pentachloride combines a strong Lewis acid character with an unusually high oxidation potential creating a powerful reagent for oxidative transformations. Since the oxidative coupling reaction of aryls is induced at an extraordinarily high reaction rate, a variety of labile groups, e.g. iodo, tert-alkyl, etc., are tolerated on the aromatic core. Furthermore, the co-formed molybdenum salts can either be exploited for template effects to obtain uncommon geometries in a preferred manner, or redox-play starts after aqueous workup. Therefore MoCl5 represents a unique and easily available reagent.

ChemInform Abstract: Molybdenum Pentachloride. A Multifaceted Reagent for Efficient Coupling of Aromatics

Versatile oxidative approach to carbazoles and related compounds using MoCl5.

The unique oxidizing power of molybdenum pentachloride provides an easy to perform, versatile, and high yielding method to construct carbazoles and the corresponding dibenzo analogues of thiophene, furan, and selenophene. The coupling reaction tolerates a variety of functional groups. The synthesis is highly modular. By this approach a precursor for the naturally occurring carbazole koenigicine was prepared.

ChemInform Abstract: Versatile Oxidative Approach to Carbazoles and Related Compounds Using MoCl5.

Oxidative intramolecular coupling of tertiary amines with at least two electron-rich arenes gives carbazoles in good to excellent yields.

Synthesis of highly functionalized 9,10-phenanthrenequinones by oxidative coupling using MoCl5.

The strong oxidative power of molybdenum pentachloride gives rise to an efficient oxidative C-C bond formation of benzil derivatives to the corresponding 9,10-phenanthrenequinones. A highly complementary method to previous approaches was developed. The required derivatives are accessible in a modular fashion and in excellent yields. By this approach the orchid-derived natural product cypripediquinone A was synthesized for the first time.

ChemInform Abstract: Synthesis of Highly Functionalized 9,10-Phenanthrenequinones by Oxidative Coupling Using MoCl5.

An efficient method to prepare functionalized 9,10-phenanthrenequinones including the natural cypripediquinone A (VIIIa) is reported.