研究室工作進展 Aug. 8th, 2016
Direct Synthesis of Phospholyl Lithium from White Phosphorus
Ling Xu, Yue Chi, Shanshan Du, Wen-Xiong Zhang,* and Zhenfeng Xi
Angew. Chem. Int. Ed. 2016, 55, 9187-9190.
Selective construction of P?C bonds directly from P4 and nucleophiles is an ideal and step-economy approach to utilize elemental P4 for straightforward synthesis of organophosphorus compounds. In this work, highly efficient one-pot reaction between P4 and 1,4-dilithio-1,3-butadienes is realized, affording phospholyl lithium derivatives quantitatively. DFT calculation indicates that the mechanism is significantly different from that of the well-known stepwise cleavage of P?P bond in P4 activation. Instead, a cooperative nucleophilic attack of two Csp2?Li bonds on P4 leading the simultaneous cleavage of two P?P bonds is favorable. This understanding of the mechanism offers a new view on the mechanism of P4 activation as well as a reasonable explanation on the excellent yields and selectivity. This methodology demonstrates a prospective route for P4 activation and consequent production of organophosphorus compounds.
亮點介紹
從白磷到有機膦化合物的傳統合成路線複雜而冗長，絕大部分情況下都涉及到劇毒、強腐蝕、易燃（如PCl3, PCl5, PH3）等反應條件并對環境造成巨大污染。從白磷出發直接高效高選擇性合成有機膦化合物是一個理想的方法，受到人們的關注。最近，我們利用丁二烯基橋聯的雙锂試劑與白磷直接反應，在溫和的條件下高産率制備了磷雜環戊二烯的锂鹽。雙锂試劑的兩個锂，如同挖掘機的鏟鬥，直接從白磷的四個磷原子中“鏟走”一個磷形成磷雜環戊二烯的锂鹽。這種雙金屬試劑直接與白磷反應，一步高效構建有機膦化合物的新方法為白磷高效利用提供了新思路。