Sun Xiaofei, Hinz Alexander, Kucher Hannes, Gamer Michael T, Roesky Peter W
Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
Chemistry. 2022 Oct 4;28(55):e202201963. doi: 10.1002/chem.202201963. Epub 2022 Aug 3.
The reaction of the dilithium salt of the enantiopure (S)-BINOL (1,1'-bi-2-naphthol) with two equivalents of the amidinate-stabilized chlorosilylene [L SiCl] (L =PhC(NtBu) ) led to the formation of the first example of a chiral cyclic silene species comprising an (S)-BINOL ligand. The reactivity of the Si=C bond was investigated by reaction with elemental sulfur, CO and HCl. The reaction with S led to a Si=C bond cleavage and concomitantly to a ring-opened product with imine and silanethione functional groups. The reaction with CO resulted in the cleavage of the CO molecule into a carbonyl group and an isolated O atom, while a new stereocenter is formed in a highly selective manner. According to DFT calculations, the [2+2] cycloaddition product is the key intermediate. Further reactivity studies of the chiral cyclic silene with HCl resulted in a stereoselective addition to the Si=C bond, while the fully selective formation of two stereocenters was achieved. The quantitative stereoselective addition of CO and HCl to a Si=C bond is unprecedented.
对映体纯的（S）-联萘酚（1,1'-联-2-萘酚）的二锂盐与两当量的脒基稳定的氯硅烯[L SiCl]（L = PhC(NtBu)）反应，生成了首例包含（S）-联萘酚配体的手性环状硅烯物种。通过与元素硫、一氧化碳和氯化氢反应，研究了硅碳双键的反应活性。与硫反应导致硅碳双键断裂，同时生成具有亚胺和硅烷硫酮官能团的开环产物。与一氧化碳反应导致一氧化碳分子裂解成一个羰基和一个孤立的氧原子，同时以高度选择性的方式形成一个新的立体中心。根据密度泛函理论计算，[2+2]环加成产物是关键中间体。对手性环状硅烯与氯化氢的进一步反应活性研究表明，氯化氢对硅碳双键进行了立体选择性加成，同时实现了两个立体中心的完全选择性形成。一氧化碳和氯化氢对硅碳双键的定量立体选择性加成是前所未有的。
