Transition-metal-catalyzed hydrothiolation of cyclohexylallene with benzenethiol or diphenyl disulfide

Abstract

This paper is dedicated to Professor Juzo Nakayama on the occasion of his 65th birthday and retirement.The reaction of benzenethiol (or diphenyl disulfide) with cyclohexylallene, as a representative terminal allene, has been investigated in detail in the presence of transition metal-phosphine complexes as the catalyst. Pd(PPh 3 ) 4 -catalyzed hydrothiolation of cyclohexylallene with benzenethiol in acetonitrile affords the corresponding terminal vinylic sulfide [RCH 2 C(SPh)=CH 2 (R = c Hex)] regioselectively in good yield, whereas Pt(PPh 3 ) 4 -catalyzed hydrothiolation of cyclohexylallene gives the regioisomeric vinyl sulfide successfully. Similar hydrothiolation of the allene proceeds using diphenyl disulfide, instead of benzenethiol, in the presence of triphenylphosphine and water.

Organometallic Approaches to Carbon–Sulfur Bond Formation

“…Likewise, monothiolation is obtained when disulfides are used with Pd(PPh 3 ) 4 when H 2 O is present [245]. This process is thought to involve H 2 O and PPh 3 -mediated reduction of the disulfide to the corresponding thiol.…”

“…However, because Pd(PPh 3 ) 4 is typically useful for related additions of heteroatoms to allenes, Ogawa explored the use of this catalyst in greater detail. Through solvent optimization, it was determined that the use of acetonitrile rendered the reaction regioselective (25) [245]. It is noteworthy that a regioisomeric product is obtained when Pt(PPh 3 ) 4 is used (Fig.…”

“…Optimized regioselectivity for allene hydrothiolation [245] Monothiolation can be achieved with disulfides using RhH(PPh 3 ) 4 as the catalyst [246]. Likewise, monothiolation is obtained when disulfides are used with Pd(PPh 3 ) 4 when H 2 O is present [245].…”

Synthesis of Functionalized Arenopyrans and Arenylsulfanes by Reacting Nitroallylic Acetates with Arenols and Arenethiols

“…Thioethers are also excellent ligands in co‐ordination chemistry . Allyl aryl thioethers, in particular, are synthesized through electrophilic substitution of allylsilanes, transition metal catalyzed coupling reactions, reaction of arenethiol with allylic acetate/carbonate, allylic halide, allylic alcohol and allene, reaction of aryl halide with allyl thiol, and other miscellaneous methods such as decarbonylative C‐S coupling of thioethers, dechalcogenative rearrangement of disulfides etc.…”

Copper-Catalyzed Regio- and Stereoselective Hydrothiolation of Allenamides, Enamides, and Ynamides

“…In comparison, relatively few works related to the inter- or intramolecular hydrothiolation of allenes have been described. Those are mainly based on the use of palladium, gold, and rhodium complexes as catalysts and lead to the formation of vinylic or allylic thioethers by addition of the thiol on the C 1 (Rh) or C 2 (Pd or Au) allenic carbon atoms (Scheme B). Over the past several years, our team has reported on a series of copper-catalyzed regio- and E -stereoselective additions of C-, N-, and O-(pro)­nucleophiles to the C 3 allenic carbon of terminal allenes and allenamides .…”