Copper-catalyzed asymmetric cyclization of alkenyl diynes: method development and new mechanistic insights

Abstract

Metal carbenes have proven to be one of the most important and useful intermediates in organic synthesis, but catalytic asymmetric reactions involving metal carbenes are still scarce and remain a...

Theoretical insights into the mechanism and origin of chemoselectivity in the catalyst- and directing group-dependent oxidative cyclization of diynes with pyridine N-oxides

“…Then, intermediate D produced through carbene migration transforms into a more stable vinyl copper carbene E in a step that is thermodynamically favored by 34.5 kcal mol −1 . Ultimately, vinyl copper carbene E is subjected sequentially to [1,4]-H shift 15 and substrate exchange to smoothly afford the final pyrrole product 3a. The entire process is highly exergonic with a free energy release of 103.9 kcal mol −1 .…”

Recent Advances in Non-Precious Metal Catalysis

“…The use of a bulky and electron-rich diazonium salt was crucial to achieve efficient iodine activation, presumably due to the enhanced stability of the aryl radical. Other notable advances in Cu-catalyzed reactions include the following publications: (1) Cu-catalyzed diazidation reactions; 54 (2) Diastereo-and enantioselective oxidative 1,6conjugate addition; 55 (3) C−H amination of 8-aminoquinoline-directed ferrocenes; 56 (4) Cu-catalyzed hydroxymethylation of alkynes with formic acid; 57 (5) Cu-catalyzed synthesis of indolyl benzo[b]carbazoles; 58 (6) Cu-catalyzed tandem cross-coupling and alkynylogous aldol reaction to access exocyclic α-allenols; 59 (7) Tandem Cu-and Rh-catalysis for oxidation of hydrazones and enantioselective cyclopropanation; 60 (8) Cu-catalyzed CF 2 H-substituted 2-amidofurans; 61 (9) Cu-catalyzed annulation of indolyl α-diazocarbonyl to access carbazoles; 62 (10) Cu-catalyzed enantioselective 1,2reduction of cycloalkenones; 63 (11) Cu-catalyzed enantiodivergent alkynylation of isatins; 64 (12) Cu-catalyzed β-lactam formation from oximes and methyl propiolate; 65 (13) Cucatalyzed aminosulfonylation of O-homoallyl benzimidates; 66 (14) Cu-catalyzed multicomponent trifluoromethylphosphorothiolation of alkenes; 67 (15) Cu-catalyzed chloroarylsulfonylation of styrene derivatives; 68 (16) Cu-catalyzed synthesis of 5-carboxyl-4-perfluoroalkyl triazoles; 69 (17) Crossnucleophile coupling of β-allenyl silanes with tertiary C−H bonds to access 1,3-dienes; 70 (18) Cu-catalyzed C(sp 3 )−H functionalization of O-pentafluorobenzoyl ketone oximes; 71 (19) Total regioselectivity of hydrobromination of alkenes controlled by Fe or Cu catalyst; 72 (20) Enantioselective synthesis of trifluoromethyl cyclopropylboronates by Cu catalysis; 73 (21) Cu-catalyzed asymmetric cyclization of alkenyl diynes; 74 (22) Synergistic Ir/Cu catalysis for asymmetric allylic alkylation of oxindoles; 75…”

“…Other notable advances in Cu-catalyzed reactions include the following publications: (1) Cu-catalyzed diazidation reactions; (2) Diastereo-and enantioselective oxidative 1,6-conjugate addition; (3) C–H amination of 8-aminoquinoline-directed ferrocenes; (4) Cu-catalyzed hydroxymethylation of alkynes with formic acid; (5) Cu-catalyzed synthesis of indolyl benzo­[ b ]­carbazoles; (6) Cu-catalyzed tandem cross-coupling and alkynylogous aldol reaction to access exocyclic α-allenols; (7) Tandem Cu- and Rh-catalysis for oxidation of hydrazones and enantioselective cyclopropanation; (8) Cu-catalyzed CF 2 H-substituted 2-amidofurans; (9) Cu-catalyzed annulation of indolyl α-diazocarbonyl to access carbazoles; (10) Cu-catalyzed enantioselective 1,2-reduction of cycloalkenones; (11) Cu-catalyzed enantiodivergent alkynylation of isatins; (12) Cu-catalyzed β-lactam formation from oximes and methyl propiolate; (13) Cu-catalyzed aminosulfonylation of O -homoallyl benzimidates; (14) Cu-catalyzed multicomponent trifluoromethyl­phosphorothiolation of alkenes; (15) Cu-catalyzed chloro-arylsulfonylation of styrene derivatives; (16) Cu-catalyzed synthesis of 5-carboxyl-4-perfluoroalkyl triazoles; (17) Cross-nucleophile coupling of β-allenyl silanes with tertiary C–H bonds to access 1,3-dienes; (18) Cu-catalyzed C­( sp 3 )–H functionalization of O -pentafluorobenzoyl ketone oximes; (19) Total regioselectivity of hydrobromination of alkenes controlled by Fe or Cu catalyst; (20) Enantioselective synthesis of trifluoromethyl cyclopropylboronates by Cu catalysis; (21) Cu-catalyzed asymmetric cyclization of alkenyl diynes; (22) Synergistic Ir/Cu catalysis for asymmetric allylic alkylation of oxindoles; (23) Hydrosilylation of alkynes and alkenes with Cu-photocatalysis under continuous flow conditions; (24) Cu-based water oxidation catalysts with consecutive ligand-based electron transfer; (25) Heteroleptic copper-based complexes for energy-transfer processes: E → Z isomerization and tandem photocatalytic sequences; (26) Copper-catalyzed aminoheteroarylation of unactivated alkenes through distal heteroaryl migration; (27) Copper-catalyzed syntheses of multiple functionalized allenes via three-component reaction of enynes; (28) Unified mechanistic concept of the copper-catalyzed and amide-oxazoline-directed C­(sp 2 )–H bond functionalization; (29) Cu-catalyzed C–H allylation of benzimidazoles with allenes; (30) Synthesis of 1,2-aminoalcohols through enantioselective aminoallylation of ketones by Cu-catalyzed reductive coupling; (31) Copper-catalyzed N-directed distal C­(sp 3 )–H sulfonylation and thiolation with sulfinate salts; and (32) Dehydrogenative aza-[4 + 2] cycloaddition of amines with 1,3-dienes via dual catalysis …”

Enantioselective Copper‐Catalyzed Formal [2+1] and [4+1] Annulations of Diynes with Ketones via Carbonyl Ylides

“…More importantly, examples of the relevant asymmetric catalysis have been quite scarce. Very recently, we disclosed that the vinyl cations could be generated via facile diyne cyclization, and importantly, a series of asymmetric transformations were established based on this strategy via a remote control of enantioselectivity, [7] including intramolecular aromatic C(sp 2 )−H functionalization, [7a] vinylic C(sp 2 )−H functionalization, [7c] cyclopropanation, [7a] [1,2]‐Stevens‐type rearrangement [7d] and intermolecular annulation with styrenes [7b] . Inspired by the above results and by our recent study on developing ynamide chemistry for heterocycle synthesis, [8, 9] we envisioned that the vinyl cation intermediates A , formed through cyclization of N ‐propargyl ynamides, [10] would be trapped by carbonyl compounds to afford intermediates B , or their resonance form, the free carbonyl ylides B′ .…”