Conversion of alkanes to linear alkylsilanes using an iridium–iron-catalysed tandem dehydrogenation–isomerization–hydrosilylation
作者:Xiangqing Jia、Zheng Huang
DOI:10.1038/nchem.2417
日期:2016.2
The conversion of inexpensive, saturated hydrocarbon feedstocks into value-added speciality chemicals using regiospecific, catalytic functionalization of alkanes is a major goal of organometallic chemistry. Linear alkylsilanes represent one such speciality chemicalâthey have a wide range of applications, including release coatings, silicone rubbers and moulding products. Direct, selective, functionalization of alkanes at primary CâH bonds is difficult and, to date, methods for catalytically converting alkanes into linear alkylsilanes are unknown. Here, we report a well-defined, dual-catalyst system for one-pot, two-step alkane silylations. The system comprises a pincer-ligated Ir catalyst for alkane dehydrogenation and an Fe catalyst that effects a subsequent tandem olefin isomerizationâhydrosilylation. This method exhibits exclusive regioselectivity for the production of terminally functionalized alkylsilanes. This dual-catalyst strategy has also been applied to regioselective alkane borylations to form linear alkylboronate esters. The selective conversion of abundant and inexpensive alkane feedstocks into value-added speciality chemicals is a significant and challenging goal, and methods for catalytically converting alkanes into useful linear alkylsilanes are unknown, to date. Now, a strategy combining alkane dehydrogenation with regioselective olefin isomerizationâhydrosilylation to produce linear alkylsilanes is described.
将廉价的饱和碳氢化合物原料转化为增值的特种化学品,利用区域选择性的催化官能化烷烃是有机金属化学的主要目标。线性烷基硅烷就是这样的特种化学品——它们有着广泛的应用,包括释放涂层、硅橡胶和成型产品。直接地、选择性地在伯碳氢键上官能化烷烃是很困难的,迄今为止,催化地将烷烃转化为线性烷基硅烷的方法是未知的。在这里,我们报道了一种定义明确的、双催化剂系统,用于一步、两步烷烃硅烷化。该系统由一个用于烷烃脱氢的夹钳配位的铱催化剂和一个用于随后的烯烃异构化-氢硅烷化的铁催化剂组成。这种方法表现出对端功能化烷基硅烷的排他性区域选择性。这种双催化剂策略也已应用于区域选择性的烷烃硼化,形成线性烷基硼酸酯。选择性地将丰富且廉价的烷烃原料转化为增值的特种化学品是一个重大且具有挑战性的目标,迄今为止,催化地将烷烃转化为有用的线性烷基硅烷的方法是未知的。现在,一种结合烷烃脱氢与区域选择性烯烃异构化-氢硅烷化来产生线性烷基硅烷的策略被描述。