Denitrative Cross-Couplings of Nitrostyrenes

Abstract

Interestingly, β-nitrostyrenes, typically bench stable compounds, are highly promising cross-coupling partners, due to their excellent availability and well understood reactivity. In this review, we report on the discovery and advancements, in the field of stereoselective, denitrative cross-couplings of β-nitrostyrenes with miscellaneous organic reagents. The rapidly expanding field offers alternative access to a broad range of functionalized alkenes, including β-alkylated styrenes, chalcones, stilbenes, cinnamic acids, and conjugated sulfones and phosphonates. The most important mechanistic pathways are briefly discussed, to familiarize readers with the elementary reactions occurring during the coupling.

The Last Fortress of Tin's Tyranny – Protodenitration of Nitroalkanes

“…The reactivity richness has been so overwhelming that in 1985 Seebach described the nitro group as having “chameleon qualities” (from German “ Chamäleon‐Qualitäten ”) [5a] . This expression inspired chemists to nickname the nitro group “synthetic chameleon.” [5b,c] However, in contrast to its versatile reactivity patterns, the nitro group appears to be far less abundant in natural or industrial end products such as pharmaceuticals or agrochemicals. To fully harness the synthetic potential of nitro compounds, organic chemists needed a reductive cleavage to corresponding alkanes, characterised as protodenitration (Scheme 1).…”

Unusual Reactivities of ortho-Hydroxy-β-nitrostyrene

“…Indeed, β-nitrostyrene serves as a good electrophile for the conjugate addition to afford α-substituted β-(nitro)ethylbenzenes [ 2 ], and serves as a good dienophile for the Diels–Alder reaction [ 3 , 4 , 5 ] or dipolarophile for cycloaddition with 1,3-dipole [ 6 , 7 , 8 ] to construct versatile cyclic systems. Nitrostyrenes also undergo denitrative cross-coupling reactions, affording disubstituted alkenes [ 9 ]. In addition, chemical conversion of the nitro group, such as reduction followed by diazotization and Sandmeyer reactions, facilitates the approach to versatile compounds from a nitro compound [ 10 , 11 ].…”

Visible Light‐Mediated Reactions of β‐Nitroalkenes

“…Also, denitrogenative substitutions are extremely useful in preparing novel styrene derivatives. [45][46][47][48] These reactivities of nitroalkenes attracted many research groups to develop methodologies to use them in visible light-mediated photo-redox reactions using a variety of photocatalysts (Figure 1). However, a review devoted to the visible light-mediated reactions of nitroalkenes has not appeared so far.…”