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Combined verification using 1-D proton and HSQC has been proved to be quite successful; the acquisition time of HSQC spectra, however, can be limiting in its high-throughput applications. The replacement with Hadamard HSQC can significantly enhance the throughput. We hereby propose a protocol to optimize the grouping of the predicted carbon chemical shifts from the proposed structure and the associated Hadamard frequencies and bandwidths. The resulting Hadamard HSQC spectra compare favorably with their Fourier-transformed counterparts, and have demonstrated to perform equivalently in terms of combined verification, but with several fold enhancement in throughput, as illustrated for 21 commercial available molecules and 16 prototypical drug compounds. Further improvement of the verification accuracy can be achieved by the cross validation from Hadamard TOCSY, which can be acquired without much sacrifice in throughput. Copyright © 2009 John Wiley & Sons, Ltd.

The structural elucidation of complex materials by NMR is complicated by the common occurrence of nearly coincident resonances. Congested regions necessitate increased spectral resolution, with additional time increments needed for 2D NMR spectroscopy, resulting in longer acquisition times. These demands conflict with the ever-increasing demands for instrument time and with long-term sample stability. Selective spectroscopy addresses both of these problems. By focusing attention only on the region of interest, fewer increments are needed. Shorter acquisitions are obtained, with a higher information content. Alternatively, the spectroscopist may choose to use these time savings to collect additional transients, allowing the study of smaller amounts of material, or low-level impurities/isomers. Using a carbohydrate as our example, we illustrate the utility of this methodology using selHMQC, selHMBC (IMPRESS) and selHMQCTOCSY. We have found this methodology useful in the coupling of efficiency and productivity of NMR spectroscopy. Copyright © 2002 John Wiley & Sons, Ltd.