Baldwin's rules for ring closure have become a useful tool for chemists and were applied efficiently in the last decades since their publication in 1976 [1]. On the one hand, they were originally limited (specially for nucleophilic additions) to first row elements taking into account the differences in geometries, bond lengths and even mechanisms for second- and higher-row elements. On the other hand, the rules, or at least the nomenclature, have been assumed to be applicable to transition metal-promoted reactions, especially for insertions of Palladium intermediates in Heck-type reactions [2,3]. Nevertheless, a systematic study of their validity in these metal-including systems has not been reported yet. In this work, a set of intramolecular carbometalations of alkenes and alkynes have been investigated using density functional theory (DFT). The size of the formed rings varied between 3-7 and the effect of different metals were studied involving group 10-12 elements (Figure 1). Pd-mediated alkylmetalations of alkenes clearly shows a concordance with postulated rules. Similar trends were found for the other two Group 11 elements (Ni and Pt). Group 10 (Co, Ru, Rh) and 12 (Cu, Ag, Au) serve to explore the trend and generality of the conclusions. References 1) Baldwin, J. E. Chem. Commun. 1976, 734-736. 2) De Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. 3) Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2006, 106, 4644-4680. Acknowledgments We thank SGIker (UPV/EHU) for providing computational resources. Financial support from the FP7 Marie Curie Actions of the European Commission via the ITN ECHONET Network (MCITN-2012−316379) and from the University of the Basque Country UPV/EHU is gratefully acknowledged.

Rules for metal-promoted ring closure: Alkylmetalation reactions of group 10-12

251st National Meeting (2016)

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