Bridged 1-Methylbisimidazoles as Building Blocks for Mixed Donor Bi- and Tridentate Chelating Ligands
作者:Nathalie Braussaud、Thomas Rüther、Kingsley J. Cavell、Brian W. Skelton、Allan H. White
DOI:10.1055/s-2001-12351
日期:——
Novel bi- and tridentate imidazole chelate ligands consisting of varying donor sets were prepared using an efficient one- or two-step procedure. Keto- and methylene-bridged bisimidazoles 1, 2 served as versatile starting materials for the introduction of additional donor groups, thus allowing the facile variation of donor sets within a bisimidazole ligand framework.
Synthesis and Structure of Intermediates in Copper-Catalyzed Alkylation of Diphenylphosphine
作者:Matthew F. Cain、Russell P. Hughes、David S. Glueck、James A. Golen、Curtis E. Moore、Arnold L. Rheingold
DOI:10.1021/ic100816u
日期:2010.9.6
or 17 with PHPh2 to yield equilibrium mixtures containing 12 and the tertiaryphosphines 4 or 7; equilibrium constants for these reactions were 8(2) and 7(2), favoring complexation of the smaller secondary phosphine in both cases. These observations are consistent with a proposed mechanism for catalytic P−C bond formation involving deprotonation of the cationic diphenylphosphine complex [Cu(triphos)(PHPh2)][PF6]
Mild Synthesis of Organophosphorus Compounds: Reaction of Phosphorus-Containing Carbenoids with Organoboranes
作者:Monika I. Antczak、Jean-Luc Montchamp
DOI:10.1021/ol800085u
日期:2008.3.1
Organoboranes react with phosphorus-containing carbenoids to produce a variety of functionalized organophosphorus compounds under mild conditions. In some cases, selective migration of one group attached to boron can be observed. Phosphonite-borane complexes are introduced as novel synthons for the synthesis of phosphinic esters.
Bisphosphine-Functionalized Cyclic Decapeptides Based on the Natural Product Gramicidin S: A Potential Scaffold for Transition-Metal Coordination
作者:Sebastian Burck、Sander G. A. van Assema、Bas Lastdrager、J. Chris Slootweg、Andreas W. Ehlers、José M. Otero、Bruno Dacunha-Marinho、Antonio L. Llamas-Saiz、Mark Overhand、Mark J. van Raaij、Koop Lammertsma
DOI:10.1002/chem.200901127
日期:2009.8.17
The naturalproductGramicidinS is a promising scaffold for novel oligopeptide‐based bisphosphine ligands, combining the advantageous rigid chiral backbone with the close proximity of phosphine substituents. The required unnatural, phosphine‐containing, amino acid building blocks were synthesized by means of a novel protocol that involves the enantioselective alkylation of a chiral nickel Schiff base
Intramolecular Exchange of Coordinated and Dangling Phosphine Groups in Pentacarbonyl[(diphenylphosphino)(di-<i>p-</i>tolylphosphino)methane]tungsten(0)
作者:Richard L. Keiter、Deliang Chen、Geoffrey A. Holloway、Ellen A. Keiter、Yi Zang、M. Todd Huml、Jonathan Filley、Douglas E. Brandt
DOI:10.1021/om300092x
日期:2012.6.25
determined for the isomerization of the linkage isomers (OC)5W[κ1-PPh2CH2P(p-tolyl)2] (5) and (OC)5W[κ1-P(p-tolyl)2CH2PPh2] (6). It is proposed that this intramolecular exchange involves a nucleophilicattack of the pendant phosphine on a cis carbonylgroup, followed by ring opening and a 1,2-shift.
平衡常数和速度已被确定为键异构体的异构化(OC)5 W [κ 1 -PPh 2 CH 2 P(p -甲苯基)2 ](5)和(OC)5 W [κ 1 -P(对甲苯基)2 CH 2 PPh 2 ](6)。提出这种分子内交换涉及侧基膦对顺式羰基的亲核攻击,然后开环和1,2-移位。