Regio‐ and Stereoselective Hydroelementation of SF₅‐Alkynes and Further Functionalizations.

Abstract

Herein is described a fully regio‐ and stereoselective hydroelementation reaction of SF5‐alkynes with N, O and S‐nucleophiles and further functionalization of the corresponding Z‐(hetero)vinyl‐SF5 intermediates, a suitable platform to access α‐SF5 ketones and esters, β‐SF5 amines and alcohols under mild reaction conditions. Experimental and computational comparative studies between SF5‐ and CF3‐alkynes have been performed to highlight and explain the difference of reactivity and selectivity observed between these two fluorinated motifs.

Regio‐ and Z‐Selective Alkyne Hydroamination and Hydrophenoxylation using Tetrafluoro‐λ6‐Sulfanyl Alkynes under Superbasic, Naked Anion Conditions

“…The difference in energy between the distorted fragment and optimized ground‐state geometry is the strain (or distortion) energy ( E strain ). The difference between the activation energy (Δ E ≠ ) and total strain energy corresponds to the interaction energy ( E int ), which has a negative value and counteracts the strain energy [21] . We found that the Δ E int term for the processes involving TS‐ Z and TS‐ E are nearly identical, but they differ in the Δ E strain (Figure 4b).…”

Expanding Radical Chloropentafluorosulfanylation of Alkynes

“…Yield of isolated product (the number in parentheses refers to calculated yield by 19 F NMR using PhSCF 3 as internal standard). References of methods: A, 13,21,16 available and difficult to prepare. 36 With our present method, triisopropylsilyl-acetylene 1z delivered 2z in a modest 13% isolated yield, while we obtained a quantitative yield of 2aa featuring a triethylsilyl group.…”

“…(A) Applications of SF 5 -alkynes in (a) Gold-catalyzed hydration, (b) Gold-catalyzed hydrofluorination, (c) Hydroelementation, (d) Intramolecular amination, (e) Diels–Alder reaction, (f, g) Pyrrole syntheses, , (h) Isoxazoline synthesis, (i) Isoxazole synthesis . (B) Synthesis of SF 5 -alkynes from SF 5 Cl and terminal alkynes.…”

“…Yield of isolated product (the number in parentheses refers to calculated yield by 19 F NMR using PhSCF 3 as internal standard). References of methods: A , ,, A′ , A″ , B , , C , D , E b Overall yield of the SF 5 -alkyne over two steps after HCl elimination. c Reaction performed in DCM from −40 °C to rt. d The product was misidentified as Z . e Unless otherwise noted, reactions have been performed in THF at −40 °C for 2 h. f Reaction performed at −78 °C. …”

“…Yield of isolated product (the number in parentheses refers to calculated yield by 19 F NMR using PhSCF 3 as internal standard). References of methods: A , ,, A′ , A″ , B , , C , D , E …”