Insertion of Alkynes into an ArS−Pt Bond: Regio- and Stereoselective Thermal Reactions, Facilitation by “o-Halogen Effect” and Photoirradiation, Different Alkyne Preferences Depending on the Ancillary Ligand, and Application to a Catalytic Reaction

Abstract

UV-vis spectrum of trans-8a. ዊ UV-vis spectrum of cis-Z-16c.

Hydroselenation and Carboselenation of Electron‐Deficient Alkynes with Isolable (Hydrido)(selenolato)platinum(II) Complexes and a Selenaplatinacycle Bearing a Triptycene Skeleton

“…Similar prior dissociation of a phosphane ligand was reported for the insertion of an alkyne into the Pt-S bond in trans-[Pt(SAr) 2 (PPh 3 ) 2 ] [13] and the Pt-Si bond in cis-[Pt(SiR 3 ) 2 (PMe 2 Ph) 2 ]. [14] Kuniyasu and Kambe succeeded in the isolation of (selenolato)(2-selenovinyl)platinum(II) [15a] and -palladium(II) complexes [15b] corresponding to 2 and 11.…”

“…(8) (9) The structure of 7 was elucidated by its 1 H, 13 C, and 77 Se NMR spectroscopic data, and finally verified by X-ray crystallography. [12] As depicted in Figure 5, there are two independent molecules (7A and 7B) in the unit cell, the geometries of which are slightly different in dihedral angles including the Se atom and torsion angles of methoxycarbonyl groups to the respective 1H-2-benzoselenin ring.…”

Transition-Metal-Catalyzed S–H and Se–H Bonds Addition to Unsaturated Molecules

“…[22,23]. The platinum species can contribute to the addition of thiols to alkynes [24,25] and the double-bond-isomerization to give the hydrothiolation product 2a. Even in the absence of catalyst, thiols add to alkynes under neutral conditions to afford anti-Markovnikov-type vinylic sulfides with excellent regioselectivity usually as a stereoisomeric mixture.…”

The Mechanism for Transition-Metal-Catalyzed Hydrochalcogenation of Unsaturated Organic Molecules

“…Although a pivotal role of thiyl radical is considered in this trans-insertion, the mechanism remains unclear. (22) In the case of dithiolato Pt(II) complex, trans-Pt(SAr) 2 (PPh 3 ) 2 , Kuniyasu and Kambe succeeded in the observation of stepwise double insertion of terminal alkynes followed by reductive elimination to give (Z,Z)-1,4-diarylthio-1,4-disubstituted-1,3-butadienes [49,50]. They also obtained (2-chalcogenovinyl)-selenolato Pt(II) [51] and Pd(II) complexes [52] by other methods.…”

“…The reaction of 43 with DMAD in the presence of additional PPh 3 (2 molar equiv) to impede the formation (E)-44 and to give (TripSe) 2 [49,50]. cis-PtH(SeTrip)(PPh 3 ) 2 (43) did not work as the catalyst for the reaction of TripSeH with DMAD because it would undergo coordination of DMAD preferentially furnishing Pt(dmad)(Ph 3 P) 2 persistent under the conditions.…”