<sup>18</sup>F-Trifluoromethylation of Unmodified Peptides with 5-<sup>18</sup>F-(Trifluoromethyl)dibenzothiophenium Trifluoromethanesulfonate
作者:Stefan Verhoog、Choon Wee Kee、Yanlan Wang、Tanatorn Khotavivattana、Thomas C. Wilson、Veerle Kersemans、Sean Smart、Matthew Tredwell、Benjamin G. Davis、Véronique Gouverneur
DOI:10.1021/jacs.7b10227
日期:2018.2.7
18F-labeling of 5-(trifluoromethyl)-dibenzothiophenium trifluoromethanesulfonate, commonly referred to as the Umemoto reagent, has been accomplished applying a halogen exchange 18F-fluorination with 18F-fluoride, followed by oxidative cyclization with Oxone and trifluoromethanesulfonic anhydride. This new 18F-reagent allows for the direct chemoselective 18F-labeling of unmodified peptides at the thiol cysteine
diazoacetates with cysteine residues that enabled metal‐free, S−H functionalization under visible‐light conditions. Moreover, this process could be intensified by a continuous‐flow photomicroreactor on the acceleration of the reaction (6.5 min residence time). The batch and flow protocols described were applied to obtain a wide range of functionalized cysteine derivatives and cysteine‐containing dipeptides
Continuous-flow processes for the <i>S</i>-alkynylation of cysteine-containing peptides and thioglycosides under catalyst-free, oxidant-free and mild conditions
Alkane-gem-diboronic acids have emerged as versatile organoboron catalysts for dehydrative amidation of α-amino acids. A phenol-substituted multiboron catalyst with a B–C–B structure outperformed simple arylboronic acids in the condensation of α-amino acids with suppressed epimerization of electrophiles. gem-diboronic acid catalysis were compatible with various O, N, and S-functionalized α-amino acids bearing N-protecting
Visible Light-Induced Trifluoromethylation and Perfluoroalkylation of Cysteine Residues in Batch and Continuous Flow
作者:Cecilia Bottecchia、Xiao-Jing Wei、Koen P. L. Kuijpers、Volker Hessel、Timothy Noël
DOI:10.1021/acs.joc.6b01031
日期:2016.8.19
We report a visible light-induced trifluoromethylation and perfluoroalkylation for cysteine conjugation using Ru(bpy)32+ as photocatalyst and inexpensive RFI as coupling partner. The protocol allows the introduction of a variety of perfluoro alkyl groups (C1–C10) and a CF2COOEt moiety. The reaction is high yielding (56–94% yield) and fast (2 h in batch, 12 examples). Process intensification in a photomicroreactor
我们报告可见光诱导的三氟甲基化和全氟烷基化的半胱氨酸偶联使用Ru(bpy)3 2+作为光催化剂和廉价的R F I作为偶联伙伴。该协议允许引入各种全氟烷基(C1-C10)和CF 2 COOEt部分。该反应收率高(56-94%),速度快(分批2 h,12个实例)。在光微反应器中的过程强化加速了反应(5分钟反应时间)并增加了产率(8个实施例)。量子产率研究支持自由基链机制。