Abstract As a major product from the reaction of PNP-nitrite [P = P(C6H5)3] with elementary sulfur or a PNP-polysulfide (PNP)2S12 in acetone under anaerobic conditions PNP-perthionitrite (PNPnitrosodisulfide) PNP-SSNO has been isolated. VIS/UV-spectra point to a thionitrate or perthionitrate as a precursor. The structures of PNP-SSNO and of the product obtained on treating the perthionitrite with triphenylphosphane in acetonitrile, PNP -SNO (PNP-monothionitrite, PNP-nitrososulfide), have been elucidated through X-ray diffraction and independently from new chemical and NMRspectrometric arguments. PNP-SSN O crystallizes in the orthorhombic space group P ben with a = 11.843(3), b = 16.647(5), c = 15.556(4) Å , PNP -SNO in the triclinic group P1̄ with a = 10.525(3), b = 17.196(5), c = 9.451(3) Å , a = 95.22(3), β = 92.32(3), γ = 91.65(3)°.

Tertiary benzylic stereocenters are accessed in high enantioselectivity by Ir-catalyzed branch selective addition of anilide ortho-C-H bonds across styrenes and α-olefins. Mechanistic studies indicate that the stereocenter generating step is reversible.

2,3,5-Trisubstituted tetrahydrofurans were prepared stereoselectively through a two-step process involving the addition of an acyl radical to a β-silyloxy acrylic ester followed by an acid-catalyzed desilylation-ketalization sequence and a final oxocarbenium reduction step. High levels of 1,2- and 1,3-stereocontrol were attained when (Me3Si)3SiH was used as a radical followed by a ionic hydrogen transfer agent.

The addition of acyl radicals to α,β‐unsaturated esters, followed by acetalization and reduction of the resulting hemiacetal was shown to provide a straightforward access to tetrahydrofurans, and fused tetrahydrofuran–lactones in good yield with high 1,3‐stereocontrol. Similar addition reactions to five‐ and six‐membered‐ring α‐methylenelactones led to trisubstituted lactones with high diastereocontrol, using (Me3Si)3SiH as hydrogen‐atom‐transfer agent. This strategy was applied to the first total synthesis of (+)‐No. 2106 A, a fused THF–lactone produced by an endophytic fungus isolated from the seeds of the mangrove Avicennia marina.