Substituent effect on di-π-methane reactions of benzopyrazinobarrelenes and benzoquinoxalinobarrelenes

To examine the substituent effect on the di-π-methane (DPM) rearrangement of barrelene-like skeleton, benzopyrazinobarrelene (BPB) and benzoquinoxalinobarrelene (BQB) were utilized as the photoreaction experimental platforms. By the installation of the pyrazine, the DPM reaction was limited to aza-di-π-methane reaction only, in terms of chemoselectivity. The results of the induced regioselectivity of DPM rearrangement of BPB and BQB with a wide variety of different substituents connected to the olefin/bridgehead position were examined.

Graphical abstractTo examine the substituent effect on the di-π-methane (DPM) rearrangement of barrelene-like skeleton, benzopyrazinobarrelene (BPB) and benzoquinoxalinobarrelene (BQB) were utilized as the photoreaction experimental platforms. By the installation of the pyrazine, the DPM reaction was limited to aza-di-π-methane reaction only, in terms of chemoselectivity. The results of the induced regioselectivity of DPM rearrangement of BPB and BQB with a wide variety of different substituents connected to the olefin/bridgehead position were examined.Figure optionsDownload full-size imageDownload as PowerPoint slide