Thus there are two related borylation methodologies that can be used: route (i) heat amineboranes + HNTf2 at 85 o C, and route (ii) at room temperature by combining amineboranes with Me3SiNTf2 and subsequent addition of portions of PhSiMe3. The key in both cases to enable high conversion to the azaborine is accounting for the sequestering of the HBr by-product from SEAr by the aminoborane 4-Br (forming the amineborane 3-Br). The amineborane can be converted to the aminoborane either by heating in an open vessel (under inert atmosphere) or by adding PhSiMe3 portionwise. Both regenerate the key aminoborane / HNTf2 combination which effects C-H borylation. The importance of the latter combination has been confirmed by directly using these two species to effect C-H borylation which also proceeds at room temperature. These borylation methodologies also could be used to form the [6]helicenes 6-Br and 7-Br (Scheme 4). These one-pot reactions were completed by mesityl protection using MesMgBr to afford bench stable 6-Mes and 7-Mes. In contrast, attempts to make 7-Br from the respective amineborane using excess BBr3 under a range of conditions (including at 150 °C for 72 h), led to its formation only as a minor product (by in-situ NMR spectroscopy). The mesityl protected helicenes were amenable to N-substituent transformations using standard azaborine functionalisation methodologies (Scheme 4). For example, deprotonation of 1-Mes with KHMDS and addition of MeI leads to formation of the N-Me analogue of 1-Mes, 8-Mes. While the formation of the BN-helicenes demonstrates the utility of these new borylation methods to access strained azaborines, its applicability to access other challenging (e.g. electronically deactivated towards SEAr) substrates also was assessed. Conversion was assessed in-situ and subsequently each azaborine was protected at boron and isolated as the B-Ph derivatives. In contrast to the unsuccessful borylation using Dewar's conditions (BCl3/AlCl3/∆), azaborines 9-Y and 10-Y (Fig. ) were readily accessible using the new methodologies. Furthermore, for 11-Br the regioselectivity was high with no borylation observed ortho to fluorine. This methodology also provides an efficient route to the dibrominated azaborines 13-Y, which were previously made via the borafluorene and an arylazide. Finally, this procedure is applicable to secondary amines, e.g. 14, and to chloro analogues utilising BCl3 in place of BBr3. Although the chloro derivatives are formed in lower yield, presumably due to the lower electrophilicity of B-Cl Vs. B-Br containing electrophiles.