Iron‐catalyzed acetylation of electron deficient N‐heteroarenes has been reported using triethylorthoformate as robust and inexpensive acetyl source. This new method is successfully applied for the acetylation of quinolines, isoquinoline, quinoxalines, arylpyridines, bipyridines, and benzothiazole.
An efficient and mild method for the direct phosphorylation of phenols, alcohols, and amines with P(O)–H has been reported by LiI/TBHP mediated oxidative cross‐coupling reaction. Moreover, this protocol extended to β‐keto esters for the synthesis of enol phosphates using H‐phosphonates. Notably, this developed method applied for the synthesis of organopesticides such as paraoxon, cyanophos, and methyl parathion. The key features of this protocol are mild conditions, short reaction time, good functional group tolerance, and broad substrate scope.
Asymmetric synthesis of P-stereogenic phosphonates presents a great challenge. Following this target we disclose herein a DKR strategy towards the O-P coupling reaction between an easily accessible enantiopure phenol bearing a chiral sulfinyl auxiliary and a commercially available or easily accessible racemic H-phosphinate. Although moderate to high chiral P-stereogenic organophosphorus compounds are an important class of valuable products with widespread applications particularly in asymmetric catalysis. [1] Over the last twenty years the synthesis of molecules with a P-stereogenic center has received significant attention. [2] Accordingly, several modern approaches such as enantioselective metal-couplings and C-H activation based reactions have been reported. [3] Besides, the development of chiral separation techniques provided an alternative approach. [4] However, these transformations are generally strongly limited by the generation of only specific P-stereogenic scaffolds and/or are inadequate for a large-scale synthesis. Accordingly, diastereoselective synthesis of P-stereogenic compounds, calling for a use of an enantiopure auxiliary, is still the most general and widely applied methodology to build up an array of P-stereogenic molecules. Indeed, already in 1967 Mislow had illustrated a great potential of cheap and abundant menthol for the resolution of tertiary phosphines. [5] Due to the versatility of this diastereoselective approach, this method greatly contributed to the design of P-stereogenic ligands such as DiPAMP or Mini-Phos, and their applications in asymmetric catalysis (Scheme 1a). [6] Later Jugé showed that chiral amines such as ephedrine were also very powerful chiral auxiliaries delivering the corresponding P-stereogenic oxazaphospholidine in high yield and diastereoselectivity (Scheme 1b). [7] Similar strategies developed by Han in 2013 and Framery in 2015 involved [a]
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