Olefination with sulfonyl halides and esters – sulfur-based variant of the Horner-Wadsworth-Emmons reaction

Abstract

Among carbonyl olefination reactions sulfur-based protocols play a prominent role, utilizing aryl and hetaryl sulfones in processes referred as 'classical' and 'one-pot' Julia olefinations. However, a related, but much less common method, which is based on the reactivity of sulfonyl halides and esters (sulfonates), features a different reaction mechanism. Accordingly, carbanions of the precursors add to aldehydes and ketones, cyclize to four membered ring intermediates and syn-fragment to alkenes, mimicking transformations of organic phosphonates (the Horner-Wadsworth-Emmons reaction). The presented mini-review compiles early reports from the 1990s with a series of recent articles, in which the 'overlooked' olefination method was systematically studied.

Alkylation of Nitropyridines via Vicarious Nucleophilic Substitution

“…In our synthetic studies, we applied reaction conditions reported previously (DMF, −40 °C, 30 min), 16 using an excess of strong base (KHMDS). After preliminary screening of nitroarenes, we observed that electrophilic 3-nitropyridines react efficiently with alkyl phenyl sulfones 2 and neopentyl alkanesulfonates 3 ( 17 ) to give alkylated products 4a – t ( Scheme 2 ). Under these conditions, products with various alkyls, such as Me, Et, iBu, Oct, neopentyl, etc., were isolated as single or predominant isomers, whereas minor isomers, formed in a few cases, contained alkyls attached at different positions of the aromatic ring (shown with red arrows in Scheme 2 ).…”

Stereoselective Synthesis of Tri- and Tetrasubstituted Olefins via 1,6-Additions of Diazo Compounds and Their Precursors to p-Quinone Methides

“…In particular, synthesis of tri-and tetrasubstituted alkenes in a stereoselective manner is of tremendous interest due to their presence in a plethora of natural products of biological significance as well as in material chemistry (Figure ). − The classical CC bond forming reactions such as Wittig reaction and its variants, aldol condensation, Julia olefination, McMurry coupling, etc., which involve either 1,2- or 1,4-additions and more recent metal-catalyzed reactions, are useful for the construction of complex organic frameworks. − However, CC bond forming reactions involving 1,6-addition are considerably underexplored compared to 1,2- and 1,4-additions. This is primarily due to the fact that the conjugated dienes have less positive charge density at the δ-carbon compared to that at the β-carbon.…”

Enantioselective Addition of Dialkyl Malonates to β-Arylethenesulfonyl Fluorides under High-Pressure Conditions

“…Recently, we reported synthesis of ArCH=CHSO 2 F via olefination 17 of arylaldehydes with methanedisulfonyl fluoride (FSO 2 CH 2 SO 2 F, MDSF). 18 With the set of substrates in hand, we tested a model reaction of β-phenylethenesulfonyl fluoride ( 1a ) with diethyl malonate ( Table 1 ), thereby giving adduct 2a in the presence of chiral thiourea, urea, and squaramide organocatalysts 3a – l 19 ( Figure 1 ).…”