Electrochemically Oxidative Phosphating of Aldehydes and Ketones.

Disclosed herein is the first protocol for the electrochemically oxidative phosphating of aldehydes and ketones to generate α-hydroxyphosphine oxides with diphenylphosphine as the phosphine source. Various phosphating products containing P-C bonds are basically assembled in modest to excellent yields. This electrochemical phosphating was achieved by utilizing a simple undivided cell with foam nickel electrodes at room temperature without the addition of any oxidant or metal catalyst.

Metal -free PhI(OAc)-oxidized decarboxylation of propiolic acids towards synthesis of α-acetoxy ketones and insights into general decarboxylation with DFT calculations.

A metal-free oxidative decarboxylation reaction of propiolic acids mediated by hypervalent iodine(III) reagents is described. This decarboxylative C-O bond-forming reaction used a combination of (diacetoxyiodo)benzene and aromatic, heteroaromatic or aliphatic propiolic acids to give the corresponding α-acetoxy ketones. Preliminary mechanistic studies based on both DFT calculations and high-resolution mass spectroscopy (HRMS) suggested that the reaction proceeded through decarboxylation to form a propargyl iodide intermediate.

Polyhalogenation-Facilitated Spirolactonization at the -Position of Phenols.

A novel dearomative spirolactonization/polyhalogenation of phenols that employs hypervalent iodine PhICl (iodobenzene dichloride) as both an oxidant and chlorine source with an indispensable base, or only using NBS (-bromosuccinimide) without any additives, is presented. Halide participations are a vital factor in the cascade reaction of 3'-hydroxy-[1,1'-biphenyl]-2-carboxylic acids with good selectivities and reactivities and induced the rapid constructions of multiple C-halogen bonds and directional C═O bonds in a one-step operation under mild conditions. In gaining a good understanding of the mechanism, the increase in number of bromine atoms was inferred rationally from the spirolactonization process, assisted by DFT calculations and high-resolution mass spectrometry.

Synthesis of fluorinated polycyclic dehydroaltenusin analogs through hypervalent iodine-catalyzed dearomatization.

We developed a method employing stoichiometric -chloroperbenzoic acid (-CPBA) as an oxidant and hydrogen fluoride pyridine (pyr·HF) as a fluoride source with catalytic amounts of iodobenzene (PhI) for the cyclization and fluorination-dearomatization of phenols, leading to a range of fluorocyclohexa-dienones with yields of up to 94%. This reaction provides a convenient method to synthesize fluorine-containing dehydroaltenusin analogs under mild conditions, and without expensive reagents. These analogs have potential application as inhibitors of DNA polymerase.

Synthesis of Altenuene Backbones through Iodine(III)-Participated Umpolung Diesterification and Insights into the General [1,5]-H Shift in -Dearomatization of Phenols via Quantum Chemical Calculations.

Through PhI(OAc)-oxidized dearomatization and diesterification of 3'-hydroxy-[1,1'-biphenyl]-2-carboxylic acids, a series of polycyclic compounds possessing an altenuene backbone were obtained in moderate to good yields. The Umpolung diesterification reaction was completed under mild reaction conditions without an additional nucleophilic reagent. This work offers a concise method for the synthesis of diverse natural altenuene analogues.

Copper-Catalyzed Oxidative Difunctionalization of Terminal Unactivated Alkenes.

The copper(II)-promoted free-radical oxidative difunctionalization of terminal alkenes to access ketoazides by utilizing molecular oxygen has been reported. A series of styrene derivatives have been evaluated and were found to be compatible to give the desired difunctionalized products in moderate to good yields. The role of molecular oxygen both as an oxidant and oxygen atom source in this catalytic transformation has been unquestionably demonstrated by O-labeling studies and a radical mechanistic pathway involving the oxidative formation of azidyl radicals is also designed.

Iron-catalysed sequential reaction towards α-aminonitriles from secondary amines, primary alcohols and trimethylsilyl cyanide.

We have developed a one-pot iron-catalysed sequential reaction of secondary amines with primary alcohols, trimethylsilyl cyanide and TBHP under mild reaction conditions to give the corresponding α-aminonitriles.