Regioselective and stereoselective sulfonylation of alkynylcarbonyl compounds in water

Abstract

A simple and efficient route for the synthesis of Z-β-sulfonyl-α,β-unsaturated carbonyl compounds by using water as the solvent and hydrogen source is developed.

Cs2CO3-Mediated Regio- and Stereoselective Sulfonylation of 1,1-Dibromo-1-alkenes with Sodium Sulfinates

“…K 2 CO 3 and Na 2 CO 3 (2 equiv) formed 3a in 60% and 45% yield, respectively; meanwhile, the reactions with CsF, Et 3 N, NaOAc, and KOt-Bu produced 3a in low-to-moderate yields (Table 1, entries 7-12). The screening of the solvents indicated that DMF yielded 78% 3a along with 10% 4a, whereas toluene, MeCN, and 1,4-dioxane did not yield any products (entries [13][14][15][16]. Note that the reaction did not occur below 100 °C.…”

“…Subsequently, the -addition of ArSO 2 − to intermediate A formed B. 16,23 Intermediate B was subjected to intramolecular oxa-Michael addition to yield C. 24 The ring opening of C followed by base promoted the intramolecular hydroalkylation of nitroso group to afford E. 25 Final-…”

“…15 Although the synthesis of vinyl sulfones has been widely and intensively studied, the synthesis of 1-bromo-1-sulfonylalkenes has been shown only in few reports. For instance, sulfonylation of activated alkynes with sodium sulfinates, 16 as well as sulfinic acids 17 in water as the reaction medium have been developed. In both cases, ethyl 3-bromopropiolate reacted with sodium toluenesulfinate or toluenesulfinic acid to yield ethyl 3-bromo-3-tosylacrylate (Scheme 1, eq.…”

Transition Metal‐Free Difunctionalization of C−C Bond with Sodium Sulfinates and Water Leading to (E)‐1‐Phenyl‐4‐sulfonylbut‐1‐enes

“…Sodium sulfinates, as readily accessible salts with high activity, are widely used in organic synthesis and pharmaceutical chemistry. [11][12][13][14][15][16] Therefore, a series of interesting transformations were developed by using sodium sulfinates as the sulfonyl source or alkyl source (usually aryl groups were afforded by desulfinylation). [11] Recently, many chemists have reported sulfonylation methods for cross-coupling reactions and difunctionalization reactions by utilizing sodium sulfinates as the sulfonyl source.…”

“…For couplings with CÀH, a variety of diverse CÀH bonds, including C(sp)ÀH bonds, [12b] C(sp 2 )ÀH bonds [13] and C(sp 3 )ÀH bonds, [14] could smoothly undergo the cross-coupling sulfonylation (Scheme 1a, paths I-III). Interestingly, sodium sulfi- nates could also be employed for the sulfonylation and difunctionalization of unsaturated bonds, including carbon-carbon triple bonds [15] and carbon-carbon double bonds. [16] In 2016, He's group [15a] presented the 1,2-difunctionalization of alkyne with sodium sulfinates and water under transitionmetal-free and additive-free conditions (Scheme 1a, path IV).…”