Harnessing hypervalent iodonium ylides as carbene precursors: C–H activation of N-methoxybenzamides with a Rh(iii)-catalyst

Abstract

The first ever attempt at reacting hypervalent iodonium ylides with readily available N-methoxybenzamides by using a Rh(iii)-catalyst has been well explored.

Transition‐Metal‐Catalyzed C−H Bond Functionalization of Arenes/Heteroarenes via Tandem C−H Activation and Subsequent Carbene Migratory Insertion Strategy

“…The simultaneous extrusion of ArÀ I along with its interception by transition-metal results in the formation of metal-carbene, hence acting as surrogate to the conventionally used diazo compounds. [20] v) From cyclopropenes: Small, strained ring systems such as cyclopropenes often serve as competent substrates for carbene coupling reactions. Thermal conditions or transition-metal-catalyzed ring opening rearrangements are usually the processes that lead to the formation of metalcarbene intermediates.…”

Assembly of Pyran-Fused Isoquinolines via Rhodium-Catalyzed Double Annulations of Methyl Benzimidates with Diazo Compounds

“…13 C NMR (100 MHz, CDCl3) δ 198. 9,196.3 168.6,162.1,159.2,136.4,128.9,128.0,120.5 (q,120.4,117.6,116.6 (q,111.4,53.8,52.7,47.6,42.5,32.8,32.1,28.3,28. 6,6,11,7,11,3,4gh]phenanthridine-4,13(5H,10H)-dione (product 3ah) Yield: 80% (88 mg); brown solid; mp 287-288 o C. 2, 196.7, 168.1, 161.7, 159.5, 148.3, 140.6, 137.0, 129.0, 128.6, 128.2, 128.0, 121.3, 119.8, 117.4, 114.8, 111.9, 54.1, 52.9, 47.7, 42.5, 32.7, 32.1, 28. 2,3,6,6,11,7,11,3,4gh]phenanthridine-4,13(5H,10H)-dione (product 3ai) Yield: 73% (72 mg); yellow solid; mp 227-228 o C. 1 H NMR (400 MHz, CDCl3) δ 8.71 (s, 1H), δ 8.71 (s, 1H),3.00 (s, 2H), 2.78 (s, 2H), 2.67 (s, 2H), 2.52 (s, 3H), 2.11 (s, 3H), 1.17(s, 12H). 13 C NMR (100 MHz, CDCl3) δ 197.…”

“…8 Maheswari reported a multistep protocol by using hypervalent iodonium ylides as carbene precursors for assembling the 3,4-dihydrophenanthridines, which were then converted to the free N-H products, and subsequent the [4+2] annulation with alkynes to form the pyran-fused 3,4-dihydrophenanthridines [Scheme 1 (d)]. 9 The interesting biological and optical properties of fused isoquinolines encouraged synthetic chemists to develop novel synthetic strategies to access structurally different motifs. since both N and O atoms may coordinate with the transition metal catalyst in directing-group-assisted functionalization of arene C-H bonds.…”

Selenonium ylides: synthesis, characterization, and applications to photo-induced cyclopropanation reactions

“…In 2007, Jenks et al developed C,S-sulfonium ylides based on the thiophene moiety as a useful precursor for carbenes using a photochemical activation methodology (Scheme 1a) [9]. The synthesized sulfonium ylides were stable, easy to handle, and could generate free carbenes using ultraviolet (UV) irradiation without a catalyst [10,15,17].…”