The P ummerer Reaction of Sulfinyl Compounds

Abstract

The Pummerer reaction involves the formation of an α‐functionalized sulfide from a sulfoxide bearing at least one α‐hydrogen atom. The reaction can also be described as an internal redox process where the SX group is reduced and the α carbon is oxidized. The first report by Pummerer on the reaction which now bears his name appeared in 1909 and described the formation of thiophenol and glyoxylic acid on heating phenylsulfinylacetic acid with mineral acids. The products Pummerer observed resulted from hydrolysis of the initially formed α‐substituted sulfides, which are the typical products of the reaction. The term “Pummerer reaction” was later extended to the reaction of sulfoxides with acid anhydrides. Selenium and nitrogen analogs undergo similar reactions. The former is known as the seleno–Pummerer reaction, and the latter is usually referred to as the Polonovski reaction. The sila–Pummerer reaction, which is also discussed in this chapter, is the rearrangement of sulfoxides bearing a silyl group on the α carbon. From a mechanistic point of view there are many other reactions, sometimes given specific names, such as the Sommelet–Hauser, Stevens, and Vilsmeier rearrangements, that appear to resemble the Pummerer reaction. Reactions in which the sulfoxide group acts as an oxidant in an intermolecular redox process have characteristics similar to the typical Pummerer reaction. The α‐halogenation of sulfides, in which the sulfide sulfur may first be oxidized to a halosulfonium salt that rearranges to the final product, is formally similar to the Pummerer reaction. For the sake of clarity and to be as exhaustive as possible, we have limited the scope of this chapter to the restrictive definition.

A New Approach to Erythrinanes through Pummerer-Type Cyclization

“…Clearly, the moderate yield was most likely due to steric hindrance of the lac- C ring of the erythrinane carbon core was then investigated. Treatment of sulfoxide 33a with trifluoroacetic anhydride [33] Reduction of the nitro group turned out to be much more difficult than expected, due to both steric hindrance and in dichloromethane (Ϫ78°C to 20°C) produced a mixture of cyclized compounds 35a, 36a, and 37. Formation of the competitive hydrogenolysis.…”

Formation of an unusual product in the reaction of a 1,2,5‐thiadiazolidine 1,1‐dioxide‐derived thioether with sulfuryl chloride

“…This ylide subsequently undergoes rearrangement to a-chlorosulfide (C) in a process that is reminiscent of the Pummerer rearrangement [24,25]. When (C) dissociates into an ion pair (both ions are stabilized by resonance), anion (D) undergoes a Michael-type reaction with iminium ion (A) to afford the unusual dimeric product (7).…”

A New Synthesis of 2-Sulfanyl Allylic Alcohols and .ALPHA.-Sulfanyl Ketones from Carbonyl Compounds and 1-Chloroalkyl p-Tolyl Sulfoxides with Carbon-Carbon Bond-Formation

“…The mechanism of this reaction is presumed to be the Pummerer-type reaction [26][27][28] as shown in Chart 4. At first, the reaction of the sulfoxide 3 with TFAA gives an acyloxysulfonium ion A.…”