Mukherjee Tathagata, Biswas Soumik, Ehnbom Andreas, Ghosh Subrata K, El-Zoghbi Ibrahim, Bhuvanesh Nattamai, Bazzi Hassan S, Gladysz John A
Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas, 77842-3012, USA.
Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
Beilstein J Org Chem. 2017 Nov 23;13:2486-2501. doi: 10.3762/bjoc.13.246. eCollection 2017.
The title molecules are sought in connection with various synthetic applications. The aliphatic fluorous alcohols R CHOH (R = CF(CF) ; = 11, 13, 15) are converted to the triflates R CHOTf (TfO, pyridine; 22-61%) and then to R CHI (NaI, acetone; 58-69%). Subsequent reactions with NaOCl/HCl give iodine(III) dichlorides R CHICl ( = 11, 13; 33-81%), which slowly evolve Cl. The ethereal fluorous alcohols CFCFCFO(CF(CF)CFO) CF(CF)CHOH ( = 2-5) are similarly converted to triflates and then to iodides, but efforts to generate the corresponding dichlorides fail. Substrates lacking a methylene group, R I, are also inert, but additions of TMSCl to bis(trifluoroacetates) R I(OCOCF) appear to generate R ICl, which rapidly evolve Cl. The aromatic fluorous iodides 1,3-RCHI, 1,4-RCHI, and 1,3-RCHI are prepared from the corresponding diiodides, copper, and R I (110-130 °C, 50-60%), and afford quite stable R CHICl species upon reaction with NaOCl/HCl (80-89%). Iodinations of 1,3-(R)CH and 1,3-(RCHCH)CH (NIS or I/HIO) give 1,3,5-(R)CHI and 1,2,4-(RCHCH)CHI (77-93%). The former, the crystal structure of which is determined, reacts with Cl to give a 75:25 ArICl/ArI mixture, but partial Cl evolution occurs upon work-up. The latter gives the easily isolated dichloride 1,2,4-(RCHCH)CHICl (89%). The relative thermodynamic ease of dichlorination of these and other iodine(I) compounds is probed by DFT calculations.
人们在各种合成应用中寻找标题分子。脂肪族氟代醇RₓCH₂OH（R = CF(CF₃)ₙ；n = 11、13、15）被转化为三氟甲磺酸酯RₓCH₂OTf（Tf₂O，吡啶；产率22 - 61%），然后再转化为RₓCH₂I（NaI，丙酮；产率58 - 69%）。随后与NaOCl/HCl反应得到二氯化碘(III) RₓCHICl₂（n = 11、13；产率33 - 81%），其会缓慢释放Cl₂。醚类氟代醇C₆F₁₃O(CF(CF₃)₂O)ₙCF(CF₃)CH₂OH（n = 2 - 5）同样先转化为三氟甲磺酸酯，然后转化为碘化物，但生成相应二氯化物的尝试失败。缺少亚甲基的底物RₓI也呈惰性，但向双（三氟乙酸酯）RₓI(OCOCF₃)₂中加入TMSCl似乎能生成RₓICl₂，其会迅速释放Cl₂。芳香族氟代碘化物1,3 - RₓCH₂I、1,4 - RₓCH₂I和1,3 - RₓCH₂I由相应的二碘化物、铜和RₓI（110 - 130 °C，产率50 - 60%）制备而成，并且在与NaOCl/HCl反应时能得到相当稳定的RₓCHICl₂物种（产率80 - 89%）。1,3 - (Rₓ)CH₂和1,3 - (RₓCH₂CH₂)CH₂的碘化反应（使用NIS或I₂/HIO₃）得到1,3,5 - (Rₓ)CH₂I₃和1,2,4 - (RₓCH₂CH₂)CH₂I₃（产率77 - 93%）。前者的晶体结构已确定，其与Cl₂反应生成75:25的ArICl/ArI混合物，但在后处理过程中会发生部分Cl₂释放。后者得到易于分离的二氯化物1,2,4 - (RₓCH₂CH₂)CH₂ICl₂（产率89%）。通过密度泛函理论（DFT）计算探究了这些以及其他碘(I)化合物二氯化反应的相对热力学难易程度。
