Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• oligomerizations involving [1.1.1]propellane – i.e., to make [n]staffanes – has been notoriously challenging to control when n > 1 is desired. Herein, we report selective syntheses of SF5- and CF3SF4-containing [2]staffanes from SF5Cl and CF3SF4Cl, demonstrating cases whereby oligomerization is preferentially

• -containing [2]staffane in the solid state. Keywords: pentafluorosulfanylation; [1.1.1]propellane; radical chain oligomerization; staffanes; strain-release; Introduction In various radical additions of X–Y across [1.1.1]propellane (1), functionalized oligomers known as [n]staffanes – with n > 1, where n

• formation [35][48]. For instance, in 2022, we reported a method for chloropentafluorosulfanylation of [1.1.1]propellane, i.e., to make SF5-BCP-Cl (4), that ostensibly proceeds through a radical chain propagation mechanism [36]. Under optimized conditions, we obtained product 4 in 86% yield, and the

(Bio)isosteres of ortho- and meta-substituted benzenes

• H. Erik Diepers and
• Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

• straightforward synthesis of a wide-range of disubstituted BCPs from [1.1.1]propellane allows them to be easily integrated into drug discovery programmes. The case of Darapladib is one well-known example of a productive para-benzene-to-BCP bioisosteric switch [24]. By comparison, the number of bioisosteres of

• from both compounds. The first investigation of 1,2-BCPs as an isosteric replacement for ortho-benzene was reported by Baran, Collins and co-workers [26]. They prepared a wide variety of 1,2-BCPs from a common 2-substituted [1.1.1]propellane building block, propellane 3a (Scheme 1A). Propellane 3a was

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• ]pentane (BCP) building blocks [36], we investigated their use in the oxadiazole-forming reaction. The BCP acid chloride 5 was synthesised from [1.1.1]propellane (3) via the photochemical reaction with isopropyl 2-chloro-2-oxoacetate (Scheme 4). The corresponding BCP acyl hydrazone was then obtained

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• , 76344 Eggenstein-Leopoldshafen, Germany 10.3762/bjoc.15.114 Abstract Herein we present the synthesis of symmetrically and unsymmetrically substituted 1,3-bissulfanylbicyclo[1.1.1]pentanes from disulfides and [1.1.1]propellane. Bicyclo[1.1.1]pentanes (BCPs) recently gained interest as rigid linkers and

• as bioisosters of para-substituted benzene and alkyne moieties. The most promising precursor for BCPs is [1.1.1]propellane (1). The available methods to synthesize BCPs are quite limited and many groups contribute to the development of novel methods. The insertion of 1 into disulfide bonds is known

• , but has never been thoroughly investigated. In this study, we show that an UV initiated radical reaction can be used to synthesize symmetrically and unsymmetrically substituted BCP sulfides by reaction of [1.1.1]propellane (1) with disulfides. Depending on the ratio of 1 to the disulfide, only the BCP