An unprecedented synthetic route for a metallaphosphorane complex. Nucleophilic attack of Lewis base on a trivalent phosphorus atom coordinating to a transition metal

1993 ◽  
Vol 115 (13) ◽  
pp. 5863-5864 ◽  
Author(s):  
Hiroshi Nakazawa ◽  
Kazuyuki Kubo ◽  
Katsuhiko Miyoshi
Keyword(s):  
Transition Metal ◽  
Phosphorus Atom ◽  
Lewis Base ◽  
Nucleophilic Attack ◽  
Trivalent Phosphorus ◽  
Synthetic Route

scholarly journals Transition-Metal-Free Boryl Substitution Using Silylboranes and Alkoxy Bases

Synlett ◽  
2017 ◽  
Vol 28 (11) ◽  
pp. 1258-1267 ◽  
Author(s):  
Hajime Ito ◽  
Eiji Yamamoto ◽  
Satoshi Maeda ◽  
Tetsuya Taketsugu
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Experimental Studies ◽  
Transition Metal Catalysts ◽  
Alkyl Halides ◽  
Aryl Halides ◽  
Nucleophilic Attack ◽  
Important Class ◽  
Mechanistic Studies ◽  
Induced Reaction

Silylboranes are used as borylation reagents for organohalides in the presence of alkoxy bases without transition-metal catalysts. PhMe2Si–B(pin) reacts with a variety of aryl, alkenyl, and alkyl halides, including sterically hindered examples, to provide the corresponding organoboronates in good yields with high borylation/silylation ratios, showing good functional group compatibility. Halogenophilic attack of a silyl nucleophile on organohalides, and subsequent nucleophilic attack on the boron electrophile are identified to be crucial, based on the results of extensive theoretical and experimental studies. This boryl­ation reaction is further applied to the first direct dimesitylboryl (BMes2) substitution of aryl halides using Ph2MeSi–BMes2 and Na(O-t-Bu), affording aryldimesitylboranes, which are regarded as an important class of compounds for organic materials.1 Introduction2 Boryl Substitution of Organohalides with PhMe2Si–B(pin)/Alkoxy Bases3 Mechanistic Investigations4 DFT Mechanistic Studies Using an Artificial Force Induced Reaction (AFIR) Method5 Dimesitylboryl Substitution of Aryl Halides with Ph2MeSi–BMes2/Na(O-t-Bu)6 Conclusion

scholarly journals Frustration across the periodic table: heterolytic cleavage of dihydrogen by metal complexes

2017 ◽  
Vol 375 (2101) ◽  
pp. 20170002 ◽  
Author(s):  
R. Morris Bullock ◽  
Geoffrey M. Chambers
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Molecular Complexes ◽  
Main Group ◽  
Lewis Base ◽  
Metal Compounds ◽  
Metal Catalysis ◽  
Heterolytic Cleavage ◽  
Lewis Pairs

This perspective examines frustrated Lewis pairs (FLPs) in the context of heterolytic cleavage of H 2 by transition metal complexes, with an emphasis on molecular complexes bearing an intramolecular Lewis base. FLPs have traditionally been associated with main group compounds, yet many reactions of transition metal complexes support a broader classification of FLPs that includes certain types of transition metal complexes with reactivity resembling main group-based FLPs. This article surveys transition metal complexes that heterolytically cleave H 2 , which vary in the degree that the Lewis pairs within these systems interact. Many of the examples include complexes bearing a pendant amine functioning as the base with the metal functioning as the hydride acceptor. Consideration of transition metal compounds in the context of FLPs can inspire new innovations and improvements in transition metal catalysis. This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.

Synthesis of an iridium porphyrin amido complex

2011 ◽  
Vol 89 (12) ◽  
pp. 1506-1511 ◽  
Author(s):  
Jenkins Yin Ki Tsang ◽  
Kin Shing Chan
Keyword(s):  
Transition Metal ◽  
Late Transition Metal ◽  
Synthetic Route ◽  
Amido Complexes ◽  
X Ray ◽  
Pyridine Solution ◽  
Aqueous Mixture ◽  
Late Transition ◽  
Established Treatment

A synthetic route for iridium porphyrin amido complexes has been established. Treatment of a THF solution of Ir(ttp)(CO)Cl (1) (ttp = 5,10,15,20-tetrakis(p-tolyl)porphyrinato dianion) with an aqueous mixture of NaOH and NaBH4, followed by 2-iodoethanol leads to the clean formation of the β-hydroxyethyl complex Ir(ttp)(C2H4OH) (2) in 92% yield. Heating a pyridine solution of complex 2 in the presence of ca. 5–10 equiv. of phthalimide (HNC8H4O2; HPhth) leads to the formation of Ir(ttp)(C5H5N)(CH2CH2Phth) (3). The replacement of pyridine by THF as the reaction solvent leads to the formation of the THF adduct Ir(ttp)(THF)(Phth) (4), which has been characterized spectroscopically. Heating a solution of 4 in pyridine leads to the formation of Ir(ttp)(C5H5N)(Phth) (5), which has been isolated in 72% yield. Complexes 3 and 5 have been characterized by X-ray crystallographic studies. Complexes 4 and 5 are rare examples of monomeric late transition metal-amido complexes and are the first examples of iridium-amido complexes featuring a porphyrin as a supporting ligand.

scholarly journals Lewis base character of the phosphorus atom in phosphanido-niobocene complexes. Synthesis of new early–early homo- and heterobimetallic entities

2011 ◽  
Vol 40 (11) ◽  
pp. 2622 ◽  
Author(s):  
R. Reguillo-Carmona ◽  
A. Antiñolo ◽  
S. García-Yuste ◽  
I. López-Solera ◽  
A. Otero
Keyword(s):  
Phosphorus Atom ◽  
Lewis Base ◽  
Early Homo

scholarly journals A Simple, General Synthetic Route toward Nanoscale Transition Metal Borides

2018 ◽  
Vol 30 (14) ◽  
pp. 1704181 ◽  
Author(s):  
Palani R. Jothi ◽  
Kunio Yubuta ◽  
Boniface P. T. Fokwa
Keyword(s):  
Transition Metal ◽  
Synthetic Route ◽  
Metal Borides

Hydrogenation of Olefins, Alkynes, Allenes, and Arenes by Borane-based Frustrated Lewis Pairs

Synthesis ◽  
2021 ◽  
Author(s):  
Felix Wech ◽  
Urs Gellrich
Keyword(s):  
Transition Metal ◽  
Hydride Transfer ◽  
Lewis Base ◽  
Catalytic Reactions ◽  
Transfer Reactions ◽  
Organic Substrates ◽  
Frustrated Lewis Pairs ◽  
Hydrogen Activation ◽  
Hydrogenation Catalysts ◽  
Lewis Pairs

In recent years, borane-based frustrated Lewis pairs proved to be efficient hydrogenation catalysts and became an alternative to transition metal-based systems. The hydrogen activation by classic FLPs leads to a protonated Lewis base and a borohydride. Consequently, hydrogenations catalyzed by classic FLPs consist of stepwise hydride transfer reactions and protonations (or vice versa). More recently, systems that operate via an initial hydroboration have allowed extending the substrate scope for FLP catalyzed hydrogenations. Within this review, hydrogenations of organic substrates catalyzed by borane-based frustrated Lewis pairs are discussed. Emphasis is given to the mechanistic aspects of these catalytic reactions.

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