Enantioselective Synthesis of 2‐Nitrotetralin Derivatives via NHC‐Catalyzed Homoenolate Reactions

Abstract We report herein a highly diastereo‐ and enantioselective homoenolate addition reaction to E –3–nitro–1,2–dihydronaphthalene via the NHC‐bound azolium homoenolate pathway, affording 2–nitrotetralins in very good chemical yields. The key 2–nitrotetralin derivatives, featuring two adjoining stereocenters, exhibit structural resemblance to the serrulatane and amphilectane diterpene natural products and pharmaceutically relevant ingredients. This catalytic asymmetric process offers a broad substrates scope, accommodating a wide range of enals and nitroalkenes embedded in tetralin or chroman frameworks, thereby yielding 2–nitrotetralin and 3–nitrochroman derivatives with three contiguous stereocenters. Other important features include: (i) readily accessible nitroalkenes and enals, including commercially available NHC‐catalyst; (ii) simplicity of the reaction conditions; and (iii) the formation of C3‐nitro‐containing tetralins and chroman cores with a high level of diastereo‐ and enantioselectivities (up to > 99:1 dr and 95% ee), along with several powerful synthetic transformations and functionalizations.