Phosphorus Pentasulfide (P4S10)

Vivek Polshettiwar

doi:10.1055/s-2004-832833

Synlett 2004(12): 2245-2246
DOI: 10.1055/s-2004-832833

SPOTLIGHT

Phosphorus Pentasulfide (P₄S₁₀)

Vivek Polshettiwar*
Process Technology Development Division, Defence R & D Establishment, Jhansi Road, Gwalior, 474002 (MP) India.
e-Mail: vivekpol2002@rediffmail.com;

Dedicated to my guide, Prof. M. P. Kaushik, on his 50th birthday.

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Biographical Sketches

Vivek Polshettiwar was born in Mangli (Village) Maharashtra (India) in 1979. He completed his B.Sc. (1999) and M.Sc. (2001) degrees in organic chemistry from Amravati University, Amravati, India. He is currently working as a DRDO-SRF for his Ph.D. under the supervision of Prof. M. P. Kaushik at Defence R & D Establishment in Gwalior, India.

Introduction

Organosulfur compounds are valued not only for their rich and varied chemistry, but also for many important biological properties. Phosphorous pentasulfide (P₄S₁₀) is very useful and versatile reagent for the synthesis of various organosulfur compounds. P₄S₁₀ is widely available as a light yellow crystalline solid. It is highly flammable and decomposes in the presence of moisture.

P₄S₁₀ has been extensively used as a thionating agent for the conversion of carbonyls into thiocarbonyls in the preparation of organosulfur compounds. It also activates the free hydroxyl group of an acid or an alcohol to create a good leaving group. It can also be used as a deoxygenating and dehydrating agent.

Abstracts


(A) As a thionating agent: Various carbonyl groups can be converted into the corresponding thiocarbonyl groups by treatment with P₄S₁₀. [1] Recently, the combination of P₄S₁₀ and HMDO has proved to be a very useful thionating reagent over P₄S₁₀ alone. [2]
(B) In the synthesis of Lawesson’s reagent: The most popular thionating reagent can be synthesized by reaction of P₄S₁₀ with anisole. [3]
(C) As an activating agent: P₄S₁₀ activates the free hydroxyl group of carboxylic acids or alcohols to create a good leaving group. When this activation is done in the presence of another nucleophile, a substitution reaction occurs. [4] It is also used for the synthesis of dithiocarboxylic esters. [5]
(D) As a deoxygenating agent: P₄S₁₀ is one of the mildest selective reagents for the conversion of sulfoxides to sulfides. [6] The reduction takes place selectively without affecting functional groups such as esters, amides or ketones. Interestingly, sulfones are also unreactive under these conditions. [7]
(E) As a dehydrating agent: Use of P₄S₁₀ as a dehydrating agent has been reported. The aromatization of a furan Diels-Alder adduct using P₄S₁₀ in CS₂ has been found to be superior than with other reagents like HCl/HOAc or polyphosphoric acid. [8]
(F) As an adduct: The reaction of steroidal molecule 16-dehydropregnenolone acetate (16-DPA) with P₄S₁₀ in refluxing benzene afforded a novel adduct 16-DPA-P₂S₅. This adduct undergoes [4+2] cycloaddition with alkyne dienophiles to afford biologically active steroidal (17,16-c)pyrans. [9]
(G) In the synthesis of thiolactams: Phosphorus pentasulfide reacts under mild conditions with organolithiums to give solutions in tetrahydrofuran. This in situ reagent converts lactams to thiolactams and shows significant selectivity in the type of reactive lactams. [10]
(H) In the synthesis of episulfides: Sterically hindered methylenecyclopropanones can be thionated with P₄S₁₀ in pyridine to afford novel 1,2,3-butatriene episulfides and a thiiranoradialene derivative. [11]