Two-coordinate palladium(0) complexes, bis(di-tert-butylphenyphosphine)palladium and bis(tri-tert-butylphosphine)palladium

Abstract

Multifidene and Aucantene, Cl1 Hydrocarbons in the Male-Attracting Essential Oil from the Gynogametes of Cutleria multij?da (Smith) Grev. (Phaeophyta) Sir :Cellular chemotaxis plays a role in the reproduction of brown algae (Phaeophyta); Le., the gynogametes (eggs) release volatile substances that act as attractants for the androgametes (sperm). In the isogamous seaweed Ectocarpus siliculosus, for example, the sex attractant has been identified as (6S)-(cis-l '-buteny1)-1,C cycloheptadiene (ectocarpene, 4), a compound which is also a constituent of the essential oils from vegetative thalli of Dictyopteris plagiogramma and D . australis. 3, In the oogamous seaweed Fucus serratus the male attractant is a 1,3,5-octatriene (f~coserratene).~ In this communication we wish to report the isolation and structure determination of the male-attracting substance and a related, biologically inactive compound (6) Male gametes were exposed to vaseline droplets containing the samples. The halo of gametes around such lures, measured against blanks, is indicative of gamone activity: D. G. Miiller, Biochem.Physiol. PP., in press.

A General Synthetic Route to Mixed NHC–Phosphane Palladium(0) Complexes (NHC=N‐Heterocyclic Carbene)

“…[3d, 4] These reports disclose complexes synthesized by ligand exchange from [Pd{PA C H T U N G T R E N N U N G (o-tol) 3 } 2 ] with NHCs {PA C H T U N G T R E N N U N G (o-tol) 3 } 3 = tri-ortho-tolylphosphane). Besides the unappealing synthesis of the [Pd{P-A C H T U N G T R E N N U N G (o-tol) 3 } 2 ] precursor, [6] only careful control of the reaction stoichiometry or the use of the highly sterically hindered IAd (1,3-bis(1-adamantyl)imidazol-2-ylidene) lead to [(NHC)Pd{PA C H T U N G T R E N N U N G (o-tol) 3 }] in good yields. Owing to the scope limitation of this synthetic procedure we decided to explore alternative routes with the aim to develop a general synthetic route to mixed NHC/PR 3 palladium(0) complexes.…”

Production of Csp3–Csp3 Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates

“…Suspecting a low reactivity due to unwanted reduction of the cationic palladium complex, Kuwano and Kondo tested other Pd catalysts under base-free conditions and finally succeeded with (η 3 -allyl)PdCp [Equation (8)], [21] which readily underwent reductive elimination leading to Pd 0 species in the presence of tertiary phosphines. [23] The (η 3 -allyl)PdCp/ DPPF combination, even in low quantities (1 %), was highly effective for the reaction of naphthylmethyl carbonates with malonates, acetamido and methoxymalonates, ethyl 2-oxocyclohexanecarboxylate, 2-acetylcyclohexanone, and azlactones [Equations (9) and (10)] but not for that of benzyl carbonates [Equation (11)]. [21] In the latter case, the reaction mixtures turned into dark brown solutions, suggesting palladium aggregation.…”

The crystal structure and absolute configuration of the complex (+)-trans-{PtCl[SiMe-(1-C10H7)Ph](PMe2Ph)2}

“…• • H contacts of 2-7 A are assumed to be essentially bonding (Immirzi & Musco, 1974;Matsumoto, Yoshioka, Nakatsu, Yoshida & Otsuka, 1974). The shape of the naphthyl group is such as to bring H(7) easily into an approximately octahedral site, and the two Pt-• • H contacts thus complete approximate octahedral coordination of the Pt atom.…”