Reduction of Bis(phosphonio)isophosphindolides to Phosphane-Functionalized Benzo[c]phospholides

Abstract

Bis(phosphonio)benzo[c]phospholides (isophosphindolides) 1a,b have been found to react with magnesium or alkali metal naphthalenides MC10H8 (M = Li, Na, K) with reduction of one or both of the phosphonio groups. The main products are the mono‐ or bis(phosphanyl)‐substituted heterocycles 2, 3, 6, 7, which have been characterized by in situ NMR studies and in some cases isolated. Subsequent reaction of 2 with excess [Ni(CO)4] gave the complex 4, which has been characterized by X‐ray diffractometry. Reactions of 1a with alkali metals followed a more complicated course and gave a mixture of 2, 3, and the substitution product 8, which was further reduced to the phosphanido‐substituted benzo[c]phospholide 9. The latter could be formed selectively by first converting 1a into 8 by treatment with PhNa and then treating this with lithium. NMR data of the phosphane‐substituted benzo[c]phospholides and the structural features of 4 are discussed.

A Zwitterionic Phosphonio-1, 2, 4-Diazaphospholide and Neutral 1, 2, 4-Diazaphosphole — A Comparative Study of Molecular Structures and Co-ordination Properties

“…We have recently established that selective reduction of cationic bis-phosphonio-benzophospholides readily gives access to zwitterionic and anionic benzophospholides [5], and began to explore the co-ordination chemistry of these products [5,6]. The attempts to extend these reactions to other cationic phospholide systems lead to the synthesis of a novel neutral phosphonio-1,2,4-diazaphospholide IV from a cationic bis-phosphonio-diazaphospholide III.…”

“…NMR analysis confirmed the presence of a mixture of the complexes 11, 12 and unreacted 2b. When the reaction of 2b (100 mg, 0.23 mmol) was carried out with two equivalents of [W(CO) 5 Crystal Structure Determination of Complexes 2b, 5, and 9a. Single crystals of 2b, 5 x 2 DME, and 9a x THF were grown from THF/hexane (2a, 9a) or DME (5) solutions.…”

Group 9 and 10 Metal Complexes of an Ylide-Substituted Phosphine: Coordination versus Cyclometalation and Oxidative Addition

“…The arene Ni interaction also results in a distinct bending of the phenyl ring which becomes evident from the C–C–C-P dihedral angle of 167.4(2)° and 159.9(2)°, which clearly differs from the ideal 180°. The P2–Ni distances of 2.233(1) and 2.215(1) Å are comparable to those for reported nickel(0) phosphine complexes …”

“…The P2–Ni distances of 2.233(1) and 2.215(1) Å are comparable to those for reported nickel(0) phosphine complexes. 12…”