Sun Qiu, Daniliuc Constantin G, Kehr Gerald, Erker Gerhard
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany.
Dalton Trans. 2021 Mar 16;50(10):3523-3528. doi: 10.1039/d1dt00459j.
The reaction of 2,4,6-tri(tert-butyl)phenyl vinyl phosphane with Piers' borane [HB(C6F5)2] gave the ethylene-bridged PH/B frustrated Lewis pair (FLP) system. It is a monomer at high temperature (>323 K), but exists as an associated 12-membered macrocyclic trimer below 273 K. The PH/B FLP splits dihydrogen and serves as a metal-free hydrogenation catalyst. It adds carbon dioxide. It serves as a PH/B template for the reduction of carbon monoxide by the HB(C6F5)2 borane to the formyl stage. The resulting six membered P/B/O containing heterocycle is opened upon treatment with pyridine and it reacts with benzaldehyde in a boron mediated Claisen-Tishchenko reaction.
2,4,6-三（叔丁基）苯基乙烯基膦与皮尔斯硼烷[HB(C6F5)2]反应生成了乙烯桥连的PH/B受阻路易斯对（FLP）体系。它在高温（>323 K）下是单体，但在273 K以下以缔合的12元大环三聚体形式存在。PH/B FLP能裂解氢气并用作无金属氢化催化剂。它能与二氧化碳加成。它作为PH/B模板，用于使HB(C6F5)2硼烷将一氧化碳还原到甲酰基阶段。所得含六元P/B/O的杂环在用吡啶处理时会打开，并在硼介导的克莱森-蒂申科反应中与苯甲醛反应。
