4525-62-6

Upstream product

• 82825-32-9 4'-(4-Bromophenoxy)spirodioxetane> 
• 64-18-6 formic acid 
• 106-41-2 4-bromo-phenol 
• 1122-91-4 4-bromo-benzaldehyde 
• 68-12-2 N,N-dimethyl-formamide 
• 79-37-8 oxalyl dichloride 
• 108-86-1 bromobenzene 
• 556-63-8 lithium formate 
• 2258-42-6 formyl acetic anhydride 

Downstream Products

• 5905-69-1 1-bromo-4-(difluoromethoxy)benzene 
• 106-41-2 4-bromo-phenol 
• 5470-34-8 4-methoxyformanilide 

Relevant academic research and scientific papers

Palladium-Catalyzed Carbonylative Synthesis of Aryl Formates under Mild Conditions

Aryl formates have been extensively applied as CO sources in CO-free carbonylation reactions. However, there are no catalytic synthetic procedures for their preparation. In this manuscript, we developed a convenient palladium-catalyzed procedure for the synthesis of aryl formates. Good yields were achieved under mild reaction conditions with formic acid as the formyl source. A formyl meeting: A convenient palladium-catalyzed carbonylation procedure for the synthesis of aryl formates is developed. Good yields are achieved under mild reaction conditions with formic acid as the formyl source.

The formyloxyl radical: Electrophilicity, C-H bond activation and anti-Markovnikov selectivity in the oxidation of aliphatic alkenes

In the past the formyloxyl radical, HC(O)O, had only been rarely experimentally observed, and those studies were theoretical-spectroscopic in the context of electronic structure. The absence of a convenient method for the preparation of the formyloxyl radical has precluded investigations into its reactivity towards organic substrates. Very recently, we discovered that HC(O)O is formed in the anodic electrochemical oxidation of formic acid/lithium formate. Using a [CoIIIW12O40]5- polyanion catalyst, this led to the formation of phenyl formate from benzene. Here, we present our studies into the reactivity of electrochemically in situ generated HC(O)O with organic substrates. Reactions with benzene and a selection of substituted derivatives showed that HC(O)O is mildly electrophilic according to both experimentally and computationally derived Hammett linear free energy relationships. The reactions of HC(O)O with terminal alkenes significantly favor anti-Markovnikov oxidations yielding the corresponding aldehyde as the major product as well as further oxidation products. Analysis of plausible reaction pathways using 1-hexene as a representative substrate favored the likelihood of hydrogen abstraction from the allylic C-H bond forming a hexallyl radical followed by strongly preferred further attack of a second HC(O)O radical at the C1 position. Further oxidation products are surmised to be mostly a result of two consecutive addition reactions of HC(O)O to the CC double bond. An outer-sphere electron transfer between the formyloxyl radical donor and the [CoIIIW12O40]5- polyanion acceptor forming a donor-acceptor [D+-A-] complex is proposed to induce the observed anti-Markovnikov selectivity. Finally, the overall reactivity of HC(O)O towards hydrogen abstraction was evaluated using additional substrates. Alkanes were only slightly reactive, while the reactions of alkylarenes showed that aromatic substitution on the ring competes with C-H bond activation at the benzylic position. C-H bonds with bond dissociation energies (BDE) ≤ 85 kcal mol-1 are easily attacked by HC(O)O and reactivity appears to be significant for C-H bonds with a BDE of up to 90 kcal mol-1. In summary, this research identifies the reactivity of HC(O)O towards radical electrophilic substitution of arenes, anti-Markovnikov type oxidation of terminal alkenes, and indirectly defines the activity of HC(O)O towards C-H bond activation.

Solvent- and catalyst-free N-formylations of amines at ambient condition: Exploring the usability of aromatic formates as N-formylating agents

A solvent- and catalyst-free N-formylation protocol has been developed for amines (1s–21s) where aromatic formates (1r–6r) were used as the N-formylating agents. The amine substrates include both primary and secondary aromatic amines (1s–19s) as well as aliphatic amine (20s) and a primary amide (21s). Structures of both the aromatic formate and amine components strongly influenced the rate of the reaction and yield of the N-formamide products. The reaction condition is mild and easy to operate. This protocol can be done smoothly under ambient conditions and gives high yield of formamide products. Furthermore, the present method cannot be applied for the formylation of thiol group (22s). This signifies its possible use for the chemoselective N-formylation of amine in the presence of thiol functionality.

Understanding the efficacy of N,N-dimethylformamide and oxalyl chloride combination as chemoselective O-formylating agent: An unified experimental and theoretical study

We have developed a simple but efficient synthetic protocol for the O-formylation of a wide range of aromatic hydroxyl/phenolic substrates using an N,N-dimethylformamide (DMF) and oxalyl chloride [(COCl)2] combination in dichloromethane (DCM) as solvent at ambient temperature. The DMF/(COCl)2combination was found to be highly chemoselective for the aromatic/phenolic hydroxyl group over aliphatic hydroxyl or aromatic amine/thiol groups. This chemoselectivity of DMF/(COCl)2combination towards O-formylation of aromatic alcohols was explained on the basis of outcomes of both experimental and density functional theory–based theoretical studies.

Three step procedure for the preparation of aromatic and aliphatic difluoromethyl ethers from phenols and alcohols using a chlorine/fluorine exchange methodology

Difluoromethyl ethers are prepared from phenols in three steps via their respective formate ester derivatives. The formates are first converted to dichloromethyl ethers by treatment with PCl5. These ethers are then induced to undergo chlorine/fluorine exchange to form the respective difluoromethyl ethers. The chlorine/fluorine exchange is carried out by either a room temperature, solvolytic process using THF-5HF or Et3N-3HF as exchange medium, where HF is the ultimate source of fluorine, or by a direct displacement process in sulfolane at 125 C, where KF is the source of fluorine. By one or another of these processes, virtually all phenols, electron-rich and electron-poor, can be converted to their respective difluoromethyl ethers in good yields. Aliphatic alcohols are also able to be converted to their difluoromethyl ether derivatives using the Et3N-3HF exchange medium.

Acceleration of the Dakin reaction by trifluoroacetic acid

An acceleration of the Dakin reaction caused by addition of trifluoroacetic acid is described. The modified protocol converts aromatic aldehydes to the corresponding phenols within 4 hours at room temperature by means of hydrogen peroxide in acidic medium. This acceleration is attributed to the stability of hydrogen peroxide in an acidic medium. This modified protocol provides alternative and easy access to important phenolic precursors that have been used in the synthesis of various natural products.

Hypervalent λ3-bromane strategy for Baeyer-Villiger oxidation: Selective transformation of primary aliphatic and aromatic aldehydes to formates, which is missing in the classical Baeyer-Villiger oxidation

A conceptually distinct, modern strategy for Baeyer-Villiger oxidation (BVO) was developed. Our novel method involves initial hydration of water to carbonyl compounds, followed by ligand exchange of hypervalent aryl-λ3-bromane on bromane(III) with the resulting hydrate, yielding a new type of activated Criegee intermediate. The intermediate undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-λ3-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate esters with high selectivity (>95%) under our conditions, while the attempted classical BVO produced only carboxylic acids. This firmly establishes the powerful nature of new methodology for BVO.

Bisphosphonic acids and esters

The present invention relates to hitherto unknown compounds of the formula I STR1 in which R1 is a straight or branched, saturated or unsaturated aliphatic or alicyclic C1 -C10 hydrocarbon radical, an aryl or an aryl-C1 -C4 -alkyl radical, R1 if desired being unsubstituted or substituted with straight or branched C1 -C4 -alkyl, amino, C1 -C4 -alkamino, di-(C1 -C4 -alkyl)-amino, carboxy, C1 -C4 -alkoxycarbonyl, hydroxy, C1 -C4 -alkoxy, phenoxy, mercapto, C1 -C4 -alkylthio, phenylthio, halogen, trifluoromethyl; R2 stands for hydrogen, C1 -C8 -alkyl, aryl-C1 -C4 -alkyl or halogen; X is O or S, and n is an integer from 0 to 2; with the proviso that R2 cannot be hydrogen or methyl if n=O and R1 is methyl. The compounds of the invention are valuable in the human and veterinary practice.

Thermal Stability of Spirodioxetanes>

The thermal stability of several spiroadamantane-substituted 1,2-dioxetanes was determined by means of chemiluminescence (Table 1).The evident stabilization of dioxetanes by such substitution cannot be interpreted in terms of "inertial mass" or "torsional" arguments in the case of concerted decomposition nor by "compressional" arguments in the case of diradical decomposition.It is suggested that a transoid diradical 19t, in which the engaged orbitals are antiperiplanar arranged, promotes C - C cleavage.The bulky adamantane substituent encumbers such conformational isome rization of the initially formed cisoid diradical 19c into the preferred 19t.