6626-15-9Relevant articles and documents
Regioselective bromination of arenes mediated by triphosgene-oxidized bromide
Xu, Yingzhou,Hu, Dufen,Zheng, Hui,Mei, David,Gao, Zhaobo
supporting information, (2019/08/30)
This article first time describes triphosgene (BTC) as an oxidant while the non-toxic and easy-to-handle potassium bromide (KBr) as the source of bromine to the bromination reaction of aromatic substrates. The novel brominating protocol gives excellent para-regioselectivity of the alkoxyl/hydroxyl arenes and high yield, offering good potential of commercial scale applications. The mechanism of “Triphosgene oxidize bromide” was proposed.
Practical regioselective halogenation of vinylogous esters: Synthesis of differentiated mono-haloresorcinols and polyhalogenated resorcinols
Chen, Xiaohong,Liu, Xiaoguang,Martinez, Jenny S.,Mohr, Justin T.
, p. 3653 - 3665 (2016/06/06)
A practical and efficient method for the direct, regioselective conversion of vinylogous esters to haloresorcinols is reported. Control of the reaction conditions enables synthesis of either the 4- or 6-haloresorcinol isomers from a common precursor with excellent regiocontrol and high yield. The generality and functional group tolerance of this novel protocol is demonstrated. The utility of this methodology to access polyhaloresorcinols is also reported. These methods create useful functionalized building blocks for further synthetic applications.
Candida antarctica lipase B-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxy groups
Miyazawa, Toshifumi,Hamada, Manabu,Morimoto, Ryohei
, p. 44 - 49 (2016/01/16)
Candida antarctica lipase B proved to be highly active in the deacylation of substituted hydroquinones and resorcinols acylated at both phenolic hydroxy groups. The deacylation reactions were much faster than the corresponding direct acylations of these dihydroxybenzenes catalyzed by the same lipase. More importantly, they took place generally in a markedly regioselective manner: the acyloxy group remote from the substituent was preferentially cleaved. The main or exclusive products obtained were the regioisomers of those produced through the direct acylation of the dihydroxybenzenes. In the case of alkyl-substituted hydroquinone derivatives, the regioselectivity increased with an increase in the bulk of the substituent. In the case of 4-substituted diacylated resorcinols, the 3-O-monoacyl derivatives were obtained generally as the sole products. Quite interestingly, some secondary alcohols proved to act as better acyl acceptors than the corresponding primary alcohols in these enzymatic deacylations.
