Abstract: Transition metal-catalyzed C–H activation strategies have led a revolution in the field of synthetic chemistry, offering powerful tools for constructing complex carbocycles and heterocycles from simple molecular building blocks.1 In this context, Ru(II)-catalysis has emerged as a particularly compelling choice, garnering widespread attention for its operational simplicity, cost-effectiveness, and impressive efficiency facilitated by weak coordination.1c However, major developments in terms of C–H annulation, alkylation, and alkenylation reactions have been realized with activated olefins and alkynes coupling partners. Engaging unactived olefins, especially allylic olefins, and carbene species for the same purpose remains immature. On this ground, we have developed an annulative coupling between hydroxamic acid esters bearing an oxidizing directing group and readily available allylic amides, dispensing biologically relevant isoquinolinones in very high yields.2a-b Further advancements towards oxidative cross-dehydrogenative alkenylations of aromatic amides and ketones with allylic and homoallylic amides have also been showcased through proper substrate design and alteration of reaction conditions.2c By employing carbene species generated in situ from diazocompounds, we were successful in preparing polycyclic benzocoumarins directly from aromatic acids, where the reaction proceeds through high-valent ruthenium(IV) intermediates.3 In contrast to the C–H activation, the C–C activation is increasingly challenging, and exploration of Ru(II)-catalysis and subsequent functionalization via the C–C activation strategy is a rare phenomenon. We have identified an efficient Ru(II)-catalyzed reaction condition that enables deformylation-guided C–C activation/arylation to access high-value BINOL analogs.4 In this seminar, the design and development of these ruthenium-catalyzed reaction methodologies will be presented.
1. (a) M. Zhang, Adv. Synth. Catal., 2009, 351, 2243. (b) L. Ackermann, Acc. Chem. Res. 2014, 47, 281. (c) P. B. Arockiam, C. Bruneau and P. H. Dixneuf, Chem. Rev., 2012, 112, 5879.
2. (a) C. K. Giri, S. Dana and M. Baidya, Chem. Commun., 2021, 57, 10536. (b) C. K. Giri, S. Dana and M. Baidya, Chem. Asian. J. 2022, 17, e202200861. (c) C. K. Giri, S. Mondal and M. Baidya, Chem. Asian. J. 2023, 18, e202300243.
3. C. K. Giri, S. Mondal and M. Baidya, Org. Chem. Front. 2023, DOI: 10.1039/d3qo01450a.
4. C. K. Giri, S. Mondal and M. Baidya, Manuscripts under preparation.