Finally, an advantage of EBXs is that the properties can be finely tuned by modification of the 2-iodobenzoic acid core of the reagent. For example the yield of transfer of the 3-F-benzene substituted alkyne could be increased from 27 to 51% by introducing a methyl group para to the carboxylic acid (product 3p). A dimethoxy-substituted reagent could also be used to give 3q in 30% yield. Our main goal was the oxyalkynylation of the C-C bond of arylcyclopropanes. However, the same conditions can be also applied to the oxyalkynylation of aminocyclopropane 5a giving products 6a and 6b in 53% and 51% yield (Scheme 3A). As reported by Chen for the photocatalytic reaction, 12 a complete inversion of the regioselectivity can be observed in this case. This is probably due to the lower stability of the radical cation, leading to ring-opening prior to attack of the nucleophile. The oxyalkynylation is not limited to -C-C bonds. Indeed, electronrich styrene derivatives 7a-c could be converted to products 8ac in 44-56% yield with complete regioselectivity via 1,2oxyalkynylation of the  bond (Scheme 3B). In this case, the same regioselectivity is observed as for enamides. 6b Finally, we turned back to the intriguing C-H alkynylation observed in the case of arylcyclopropane 1g. In fact, 1,1-arylalkynyl cyclopropanes are useful building blocks in synthetic and medicinal chemistry. 16 They have never been accessed via C-H alkynylation, which has been realized mostly on unsubstituted positions using directing group mediated transition metal catalysis. 17 We were pleased to see that the Ph-EBX (2a) mediated alkynylation of 1g was surprisingly efficient, with 83% product 4a isolated after 7 h of irradiation with only 1.5 equivalents of 2a (Scheme 3C). The reaction was easily scalable and 4a was obtained in 92% on a 2 mmol scale. The transformation was also successful with functionalized EBX reagents. Alkyl substituents in para position on the benzene ring gave products 4b and 4c in 65% and 40% yield. A trifluoromethyl group and halogens were well tolerated at this position, giving products 4d-g in 70-81% yield. Finally, products 4h and 4i, bearing a meta fluoro and an ortho bromo group respectively, were obtained in 61% and 54% yield. Based on our experimental results and our previous studies, 14 a highly speculative reaction mechanism can be proposed (Scheme 4A). Direct light activation of Ph-EBX (2a) would lead to the highly oxidizing species 2a*. Single electron transfer from arylcyclopropane 1 would give then radical anion I and radical cation II. In a previous work, we showed by computation that I was relatively stable to monomolecular decomposition. 18 The major side product observed in the photoactivation of 2a is diyne 9, probably formed in either of two bimolecular pathway: Reaction with another molecule of I to give 9 and 2 equivalents of 2-iodobenzoate , or with 2a to give 9, 10 and radical III. From radical cation II, two pathways can be considered. Ring opening with benzoate 10 to give the more stable radical IV, followed by reaction with 2a (or I) would lead to the oxyalkynylation product 3 (pathway a). Deprotonation with benzoate 10 would give radical V, which would be then alkynylated by either 2a or I resulting in the formation of 4 (pathway b). In general, we would favour alkynylation with 2a, as it would be present in higher concentration, but an involvement of I cannot be excluded, especially in the case of C-H alkynylation, which is surprisingly efficient. For C-H alkynylation, a radical chain mechanism involving radical III should also be considered. In fact, H abstraction from 1 by III would give directly radical V. However, we think that this mechanism may be less probable, as no alkynylation was observed with arylcyclopropanes lacking the methoxy group such as 1k, showing that oxidation of the substrate is probably needed for the reaction to occur. Furthermore, direct HAT on cyclopropanes is generally difficult, due to the stronger C-H bond/lower stability of the radical. 19 A striking result of our studies was the complete switch of chemoselectivity when introducing a second ortho methyl group on the arene ring. A tentative explanation may be found in the conformation analysis of the cyclopropane (Scheme 4B).