Synthesis of α-heterosubstituted ketones through sulfur mediated difunctionalization of internal alkynes

Abstract

Synthesis of α-heterosubstituted ketones and related heterocyclic structures was achieved through sulfur mediated difunctionalization of internal alkynes in one pot.

In Water Markovnikov Hydration and One‐Pot Reductive Hydroamination of Terminal Alkynes under Ruthenium Nanoparticle Catalysis

“…Hydration occurred exclusively when Shvo's catalyst was employed, while with other Ru based catalysts the addition of 5 % aniline did not work (entries [13][14][15]. The reaction also occurred under convectional heating at 120°C for 8 h in a sealed tube immersed in an oil bath (entry 12).…”

Recent advances in the synthesis of α-amino ketones

“…66 Treatment of tetrasubstituted silyl enol ethers (85) with protected hydroxylamine 86 in HFIP generated amino ketones featuring a quaternary centre (87) in up to 82% yield. Even though most of the reported examples involved the synthesis of aromatic α,α-dimethyl substituted ketones, the methodology was also found to be compatible with unsaturated substituents (88) and alicyclic ketones (89). Electron-deficient substrates did not react under these conditions, although their desired transformation was instead achieved under transition metal catalysis.…”

“…87,88 An alternative approach to alkyne functionalisation employing an activated sulfoxide was presented by Xu in 2019 (Scheme 31). 89 A useful example of a radical functionalisation of styrene derivatives was published by the Yu group in 2017. 90 This functionalisation (Scheme 32) involved the attack of a terminal alkene (149) by a nitrogen-centered radical, generated from a protected hydroxylamine (150), and further conversion of the resultant radical to a cation that reacted with DMSO to give the α-amino carbonyl (151).…”

Synthesis of γ-substituted carbonyl compounds from DMSO-mediated oxidation of enynamides: mechanistic insights and carbon- and hetero-functionalizations

“…Towards umpoled enolate (a 2 ) synthons, oxidation of alkynes through transition metal catalysis (Au, Rh, Ir, Ru, and Zn)3 and the hypervalent iodine chemistry of carbonyl compounds4 have led the way (Scheme 1a). More recently, we5 and others6,7 have reported a non-metal protocol involving Brønsted acid that can catalyze the oxidation of ynamides 1 and induce subsequent addition of carbon nucleophiles, furnishing α-heteroaryl imides 3 (Scheme 1b). In this process, it was unambiguously proved that the key intermediate, adduct 2 , underwent a concerted S N 2′ alkylation by the observation of chirality transfer from optically active N -oxides 5 a…”