簡便な活性エステル化剤

炭酸ビス(ペンタフルオロフェニル)は簡便な操作により活性エステル体を得ることができる試薬です。例えばSandersらは，カルボン酸を反応させ，活性エステル体であるペンタフルオロフェニルエステルに誘導し，続くアルコールおよびアミン類との反応で，対応する種々のエステルおよびアミド化合物を得ています。用いる添加剤も少なく，煩雑な操作も必要としません。

[1] A. Jamil, E. M. Zubin, D. A. Stetsenko, Nucleic Acids Symposium Series 2008, 52, 719

[2] “A Simple and Efficient Synthesis of Functionalized Cyclic Carbonate Monomers Using a Versatile Pentafluorophenyl Ester Intermediate”

D. P. Sanders, K. Fukushima, D. J. Coady, A. Nelson, M. Fujiwara, M. Yasumoto, J. L. Hedrick, J. Am. Chem. Soc. 2010, 132, 14724. DOI: 10.1021/ja105332k

An improved two-step synthetic route to functionalized cyclic carbonate monomers that features a novel cyclic carbonate intermediate with an active pentafluorophenyl ester group (MTC-OPhF5) has been developed. The versatile pentafluorophenyl ester intermediate can be synthesized on the gram to kilogram scale in one high-yielding step and is easy to store and handle on the benchtop. The active pentafluorophenyl ester of MTC-OPhF5 is amenable to further substitution with suitable nucleophiles such as alcohols and amines to generate functionalized cyclic carbonates in high yields. The substitution reaction is tolerant of a wide variety of functionalities, including various hydrophobic and hydrophilic groups, reactive functionalities (via thiol−ene click chemistry or alkyl halides), and protected acids, alcohols, thiols, and amines. In view of the ever-increasing need for biodegradable and biocompatible polymers, this new methodology provides a simple and versatile platform for the synthesis of new and innovative materials.