Molecular structure and basic spectroscopic properties of 3-selenocyanatoindole: An important reference compound in organoselenium research

Selenium‐NMR Spectroscopy in Organic Synthesis: From Structural Characterization Toward New Investigations

“…Selenium element has proven to be a suitable nuclide in NMR spectroscopy in studies on stability, [40] reactivity, [41,42] chirality, [43,44,45,46,47,48] polymers, [49,50,51] coordination chemistry, [52,53,54,55] and bio-based experiments. [56,57,58,59] The great potential of 77 Se NMR experiments can be attributed to selenium-77 isotope properties, as spin ( 1 = 2 ), natural abundance (7.63%), no quadrupolar moment, magnetogyric ratio (5.12 × 10 7 rad.s À 1 .T À 1 ) and negligible nuclear Overhauser effect (nOe). [60] The wide spectral window of selenium-77 isotope (δ Se = À 700 to + 2200 ppm) provides an accurate form to identify and quantify organoselenium compounds, which the Figure 1 illustrates the resonance ranges of various selenium organic functions.…”

“…All these above-mentioned properties allow to achieve high resolution NMR spectra with sharp and high-intensity signals. Comparatively, it is easier to acquire a 77 Se NMR spectrum than a 13 C NMR one once the receptivity of 77 Se related to 13 C is of 3.15. In view of this receptivity, 77 Se NMR experiment should be included in the checklist of experiments necessary to confirm a organoselenium compound, once this analysis provides additional data for structural elucidation, confirming the identity of selenium atom by a simple and rapid protocol.…”

“…In this context, the ability to predict and understand the selenium chemical shifts variation is very important. Computational models are in constant development to improve the capability to predict 77 Se NMR chemical shifts. [63] However, to maintain the efficiency of any model, a vast amount of data on experimental 77 Se NMR chemical shifts is obligatory.…”

“…[29,30] Considering the organoselenium chemistry, 77 Se NMR spectroscopy has become one of the most important technique to understand the structures and dynamic process, [31,32] as well as solid materials. [33,34,35] The advantages of 77 Se NMR include simplicity in the measurements, broad substrate applicability, structural and dynamic information, and the ability to analyze complex mixtures. This review aims to summarize the recent developments on 77 Se NMR strategies, as an important auxiliary in the development of synthetic methodologies, highlighting the gain of benefits in using this approach.…”

“…This review aims to update the role of 77 Se NMR as an analytical tool in organic synthesis, considering that NMR-based detection is a modern alternative to provide valuable data in distinct fields. [38] Furthermore, this review provides an upgrade of selenium-77 chemical shift data, covering a great amount of seleniumcontaining organic structures, and being a useful complement to the fewer publications mainly devoted to 77 Se NMR spectroscopy. [39] Márcio Santos Silva (1994), MSc (1996)…”