The unusual influence of hetaryl groups on the direct conversion of some secondary alcohols into thiols with Lawesson’s reagent: elucidation of the reaction mechanism

ABSTRACT

A series of hetaryl-substituted methanols were used for direct conversion into the corresponding thiols by treatment with Lawesson’s reagent in boiling toluene. Unexpectedly, the respective sulfides were formed exclusively. In the case of chiral alcohols, the sulfides were obtained as 1:1-mixtures of meso- and dl-diastereoisomers. In contrast to hetaryl-substituted alcohols, the analogous protocol applied for benzhydryl alcohol led to a mixture of the expected secondary thiol and a bis(diphenylmethyl) trithiophosphonate. Finally, the analogous reactions with ferrocenyl(phenyl)methanol and diferrocenylmethanol, respectively, led to the corresponding thiols in good yield.

GRAPHICAL ABSTRACT

KEYWORDS:

• Lawesson’s reagent
• secondary alcohols
• secondary thiols
• organic sulfides
• hetaryl substituents

Acknowledgement

Skillful performance of elemental analysis of all new compounds by Ms Agnieszka Cieślińska and Ms Hanna Jatczak (University of Łódź) is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors thank the National Science Center (Cracow, Poland) for generous financial support [grant Maestro-3 (Dec-2012/06/A/ST5/00219)].