Towards Extended Zinc Ethylsulfinate Networks by Stepwise Insertion of Sulfur Dioxide into Zn−C Bonds

• Published in: Chemistry : a European journal Vol. 25; no. 62; pp. 14072 - 14080
• Main Authors: Tulewicz, Adam, Wolska‐Pietkiewicz, Małgorzata, Jędrzejewska, Maria, Ratajczyk, Tomasz, Justyniak, Iwona, Lewiński, Janusz
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 07-11-2019
• Subjects: Atmospheric chemistry; Chemical bonds; Chemical reactions; Chemistry; Coordination polymers; density functional calculations; Gases; Hexamethylenetetramine; Insertion; Lewis base; Organic chemistry; Polymers; small-molecule activation; Sulfur; Sulfur dioxide; Toluene; Zinc; Zinc compounds; coordination polymers; density functional calculations; sulfur dioxide; zinc; small-molecule activation
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201902733

The ability to utilize polluting gases in efficient metal‐mediated transformations is one of the most pressing challenges of modern chemistry. Despite numerous studies on the insertion of SO2 into M−C bonds, the chemical reaction of SO2 with organozinc compounds remains little explored. To fill this gap, we report here the systematic study of the reaction of Et2Zn towards SO2 as well as the influence of Lewis bases on the reaction course. Whereas the equimolar reaction provided a novel example of a structurally characterized organozinc ethylsulfinate compound of general formula [(EtSO2)ZnEt]n, the utilization of an excess of SO2 led to the formation of the zinc(II) bis(ethylsulfinate) compound [(EtSO2)2Zn]n. Moreover, we have discovered that the presence of N‐donor Lewis bases represents an efficient tool for the preparation of extended zinc ethylsulfinates, which in turn led to the formation of 1D [(EtSO2ZnEt)2(hmta)]n and 2D [((EtSO2)2Zn)2(DABCO)]n⋅solv (in which solv=THF or toluene, hmta= hexamethylenetetramine, and DABCO=1,4‐diazabicyclo[2.2.2]octane) coordination polymers, respectively. The results of DFT calculations on the reactivity of SO2 towards selected Zn−C reactive species as well as the role of an N‐donor Lewis base on the stabilization of the transition states complement the discussion.
Make a spider's web! We have investigated the stepwise insertion of SO2 into the Zn−C bonds of selected organozinc reagents, which leads to the formation of novel organozinc alkylsulfinates and represents an efficient tool for the preparation of extended zinc ethylsulfinate networks (see figure). The mechanism of SO2 insertion is discussed in detail on the basis of DFT calculations.