ReductiveorthoC–H cyanoalkylation of aryl(heteroaryl) sulfoxides: a general approach to α-aryl(heteroaryl) nitriles

Abstract

A catalyst-free low-temperature cyanoalkylation has been developed as a general protocol for the synthesis of α-aryl(heteroaryl) nitriles.

Bond-Forming and -Breaking Reactions at Sulfur(IV): Sulfoxides, Sulfonium Salts, Sulfur Ylides, and Sulfinate Salts

“…113 The group of Peng was further able to extend the scope of sulfoxides by employing α-stannyl nitriles, thereby allowing for far milder reaction conditions. 114…”

Z‐Selective α‐Arylation of α,β‐Unsaturated Nitriles via [3,3]‐Sigmatropic Rearrangement

“…Surprisingly,f urther optimizing the temperature (T 1 )a nd time (t 1 )f or the T 2 O-initiated assembly process significantly improved the reaction efficiencyp roducing 3aa in an early quantitative yield (99 %) (entry 5). Screening of bases revealed that DABCO was superior to other bases such as NEt 3 , DBU,H ünigsb ase and pyridines (entries [7][8][9][10][11][12]. Notably, most of these organic bases were proved to be suitable for the reaction with producing good yields of 3aa.T hese results demonstrated an excellent base flexibility that can be beneficial for tuning the reaction in facing with different types of substrates.T oo ur delight, decreasing the K 2 CO 3 loading from 10.0 equiv to 3.0 equiv still afforded 3aawith the best yield (99 %) thus achieving the best conditions for the reaction (entry 13).…”

“…In the past few years, [ 3,3]-rearrangement of aryl sulfoxides have attracted great attentions from synthetic community. [4] With the rearrangement protocol, an array of nucleophiles such as allyl/propargyl silanes, [5,6] internal alkynes, [7] carbonyl compounds, [8] phenols, [9] stannyl nitriles [10] and alkyl nitriles [11] have been introduced into ortho-position of aryl sulfoxides.Inthis context, we have recently developed a[ 3,3]-rearrangement of aryl sulfoxides with alkyl nitriles using an "assembly/deprotonation" sequence that allows for ortho-C-H cyanoalkylation of aryl sulfoxides (Scheme 1a, eq 1). [11a] The" assembly/deprotonation" protocol also inspired us to develop ahighly selective [5,5]-rearrangement of aryl sulfoxides with allyl nitriles that enables the remote para-C-H alkylation of aryl sulfoxides (eq 2).…”

Selective [5,5]‐Sigmatropic Rearrangement by Assembly of Aryl Sulfoxides with Allyl Nitriles

“…The ortho C À Hfunctionalizations of aryl sulfoxides have garnered great interest in the past decades. [6][7][8][9][10][11][12] An array of functionalities including allyl, [7] propagyl, [8] carbonyl, [7,9] phenolic aryl, [10] and cyanoalkyl [11] groups were selectively anchored at the ortho position of aryl sulfoxides using electrophilic activation protocols,a sr eported by the groups of Kita, Procter, Maulide,Y orimitsu, Magnier,and others.Its worth noting that Yorimitsu and co-workers observed para C À Harylation products in the development of ortho arylation of aryl sulfoxides with phenols. [10a] They have also reported an elegant protocol for para CÀHsulfanylation of aryl sulfoxides using alkyl aryl sulfides as nuleophiles.…”