1379610-52-2Relevant articles and documents
Undeniable Confirmation of the syn-Addition Mechanism for Metal-Free Diboration by Using the Crystalline Sponge Method
Cuenca, Ana B.,Zigon, Nicolas,Duplan, Vincent,Hoshino, Manabu,Fujita, Makoto,Fernández, Elena
, p. 4723 - 4726 (2016)
The stereochemical outcome of the recently developed metal-free 1,2-diboration of aliphatic alkenes has, until now, only been elucidated by indirect means (e.g. derivatization). This is because classical conformational analysis of the resulting 1,2-diboranes is not viable; in the 1H NMR spectrum the relevant 1H resonances are broadened by 11B, and the occurrence of the products as oily compounds precludes X-ray crystallographic analysis. Herein, the crystalline sponge method is used to display the crystal structures of the diboronic esters formed from internal E and Z olefins, evidencing the stereospecific syn addition mechanism of the reaction, which is fully consistent with the prediction from DFT calculations. The crystalline sponge method provides conclusive proof of the stereospecific addition in the metal-free diboration of internal aliphatic alkenes (see scheme). The compatibility of common boryl groups with a monoporous ZnI2 network gives access to the crystal structures of the oily organoborane compounds. The relative stereochemistry of the metal-free diboration products was unequivocally assigned and fully consistent with the DFT calculations.
Copper-Catalyzed Borylative Methylation of Alkyl Iodides with CO as the C1 Source: Advantaged by Faster Reaction of CuH over CuBpin
Wu, Fu-Peng,Wu, Xiao-Feng
supporting information, p. 11730 - 11734 (2021/04/22)
CuH and CuBpin are versatile catalysts and intermediates in organic chemistry. However, studies that involve both CuH and CuBpin in the same reaction is still rarely reported due to their high reactivity. Now, a study on CuH- and CuBpin-catalyzed borylative methylation of alkyl iodides with CO as the C1 source is reported. Various one carbon prolongated alkyl boranes (RCH2Bpin and RCH(Bpin)2) were produced in moderate to good yields from the corresponding alkyl iodides (RI). In this cooperative system, CuH reacts with alkyl iodide faster than CuBpin.
Zirconium-Catalyzed Atom-Economical Synthesis of 1,1-Diborylalkanes from Terminal and Internal Alkenes
Cui, Xin,Jiao, Haijun,Li, Sida,Wang, Xianjin,Wang, Yue,Wu, Lipeng,Xia, Chungu
supporting information, p. 13608 - 13612 (2020/06/02)
A general and atom-economical synthesis of 1,1-diborylalkanes from alkenes and a borane without the need for an additional H2 acceptor is reported for the first time. The key to our success is the use of an earth-abundant zirconium-based catalyst, which allows a balance of self-contradictory reactivities (dehydrogenative boration and hydroboration) to be achieved. Our method avoids using an excess amount of another alkene as an H2 acceptor, which was required in other reported systems. Furthermore, substrates such as simple long-chain aliphatic alkenes that did not react before also underwent 1,1-diboration in our system. Significantly, the unprecedented 1,1-diboration of internal alkenes enabled the preparation of 1,1-diborylalkanes.
