Boronate Ester Bullvalenes

Patel, Harshal D.; Trần, Thanh Huyền; Sumby, Christopher J.; Pašteka, Lukáš F.; Fallon, Thomas

doi:10.1021/jacs.9b12930

Cited by 23 publications

(33 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our group recently introduced a two-step method for the synthesis of substituted bullvalenes from cyclooctatetraene through cobalt-catalyzed [6 + 2] cycloadditions with alkynes followed by photochemical di-π-methane rearrangement . Importantly, this could be extended to incorporate boronate ester functionality, leading to versatile synthetic building blocks …”

mentioning

confidence: 99%

Stereomutation of Substituted Bullvalenes

et al. 2020

Self Cite

View full text Add to dashboard Cite

The stereomutation of substituted bullvalenes is an inevitable consequence of the valence isomerism that automerizes this unique fluxional hydrocarbon. The introduction of external stereogenicity in the substituents expands the reaction graphs and leads to a wealth of complex diastereochemical relationships. In this communication, we explore these possibilities and prepare a range of stereochemically rich substituted bullvalenes. This includes a series of disubstituted bullvalenes with two external stereocenters as a platform for fluxional, shape-diverse compound libraries. We also prepare a tethered bisbullvalene with central stereogenicity in the tether as an ensemble of 900 unique isomers that are completely stereomutable.

show abstract

mentioning

confidence: 99%

Stereomutation of Substituted Bullvalenes

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…A recent revival of interest has been led by Bode, [3] Echavarren, [4] and one of our laboratories [5] . In a recent report, we developed easy synthetic access to a range of diaryl substituted bullvalenes [5c] …”

Section: Figurementioning

confidence: 99%

“…The conceivable complexity of this M 2 L 4 system is built upon the reaction graph of the bullvalene ligand. For disubstituted bullvalene networks of this type, there are 15 possible isomers including three enantiomer pairs, (Figure 3b) where nodes represent isomers and edges Cope rearrangement pathways [5c] . For bis‐3‐pyridyl bullvalene there are three populated isomers, A, B, and C, that rapidly interconvert through a lower energy circuit including intermediate isomer D. Isomer C also possesses a degenerate rearrangement pathway with itself (Figure 3b).…”

Section: Figurementioning

confidence: 99%

Guest‐Dependent Isomer Convergence of a Permanently Fluxional Coordination Cage

et al. 2022

Self Cite

View full text Add to dashboard Cite

A fluxional bis‐monodentate ligand, based on the archetypal shape‐shifting molecule bullvalene, self‐assembles with M2+ (M=Pd2+ or Pt2+) to produce a highly complex ensemble of permanently fluxional coordination cages. Metal‐mediated self‐assembly selects for an M2L4 architecture while maintaining shape‐shifting ligand complexity. A second level of simplification is achieved with guest‐exchange; the binding of halides within the M2L4 cage mixture results in a convergence to a cage species with all four ligands present as the “B isomer”. Within this confine, the reaction graph of the bullvalene is greatly restricted, but gives rise to a mixture of 38 possible diastereoisomers in rapid exchange. X‐ray crystallography reveals a preference for an achiral form consisting of both ligand enantiomers. Through a combination of NMR spectroscopy and DFT calculations, we elucidate the restricted isomerisation pathway of the permanently fluxional M2L4 assembly.

show abstract

“…Thus, the reaction appears to be uxional/shape-shiing at room temperature. [36][37][38][39][40] For this substrate, we also modelled the dissociative pathway (Scheme 2D). It was found that bond breakage to two allylic radical intermediates is a higher energy process than the concerted transition state (Scheme 2C vs. Scheme 2D).…”

mentioning

confidence: 99%