Isomerization of Terminal Epoxides by a [Pd–H] Catalyst: A Combined Experimental and Theoretical Mechanistic Study
摘要:
An unusual palladium hydride complex has been shown to be a competent catalyst in the isomerization of a variety of terminal and internal epoxides. The reaction displayed broad scope and synthetic utility. Experimental and theoretical evidence are provided for an unprecedented hydride mechanism characterized by two distinct enantio-determining steps. These results hold promise for the development of an enantioselective variant of the reaction.
dimethylphenylsilylmethylmagnesium chloride result in highly regioselective dehydrohalogenation. The reaction does not follow the conventional E2 elimination mechanism but includes beta-hydride elimination from the corresponding alkylcobalt intermediate. The interesting reaction mechanism of the cobalt-catalyzed dehydrohalogenation offered unique transformations that are otherwise difficult to attain.
Polymer-bound palladium-catalyzed cross-coupling of organoboron compounds with organic halides and organic triflates
作者:Su-Bum Jang
DOI:10.1016/s0040-4039(97)00171-8
日期:1997.3
The polymer-bound palladium-catalyzedcross-couplingreaction of electrophiles(i.e., halides and triflates) with organoboron compounds to form carbon-carbon bonds was achieved at mild conditions with very high activity in the Suzuki coupling reaction. The polymeric catalyst can be easily separated from a reaction mixture and reused more than 10 times with no decrease in activity
Stereo- and Regiospecific Synthesis of Trisubstituted Alkenes via the Palladium-catalyzed Cross-coupling Reaction of Diisopropyl (<i>E</i>)-(1-Alkyl-1-alkenyl)boronates with Organic Halides
作者:Makoto Satoh、Norio Miyaura、Akira Suzuki
DOI:10.1246/cl.1986.1329
日期:1986.8.5
The reaction of diisopropyl (Z)-(1-bromo-1-alkenyl)boronates readily obtainable, with organolithiums and bases takes place readily to give (E)-(1-organo-1-alkenyl)boronates, the cross-coupling of which with various organichalides proceeds smoothly in the presence of Pd-catalyst and base to afford stereodefined trisubstituted alkenes in good yields.
Palladium-catalyzed cross-coupling reaction of organoboron compounds with organic triflates
作者:Takayuki Ohe、Norio Miyaura、Akira Suzuki
DOI:10.1021/jo00060a041
日期:1993.4
The cross-coupling reaction of 9-alkyl-9-borabicyclo[3.3.1]nonane (9-R-9-BBN), 1-alkenyl-1,3,2-benzodioxaborole, or aryl boronic acid with 1-alkenyl or aryl triflates in the presence of K3PO4 (1.5 equiv) and a catalytic amount of Pd(PPh3)4 or Cl2Pd(dppf) resulted in high yields. The reaction conditions are sufficiently mild so that a variety of functionalized alkenes, alkadienes, and arenes are readily obtained. The utility of the present reaction was demonstrated by the cyclization of omega-alkenyl triflates leading to a benzo-fused cycloalkene and bicyclic alkene via a hydroboration-intramolecular coupling sequence.
Molybdenum metalloazines. New reagents for carbon-carbon double bond formation by an organometallic analog of the Wittig reaction
作者:John A. Smegal、Ingrid K. Meier、Jeffrey. Schwartz