144688-82-4Relevant articles and documents
Intramolecular hydroamination of unbiased and functionalized primary aminoalkenes catalyzed by a rhodium aminophosphine complex
Julian, Lisa D.,Hartwig, John F.
supporting information; experimental part, p. 13813 - 13822 (2010/11/17)
We report a rhodium catalyst that exhibits high reactivity for the hydroamination of primary aminoalkenes that are unbiased toward cyclization and that possess functional groups incompatible with more electrophilic hydroamination catalysts. The rhodium catalyst contains an unusual diaminophosphine ligand (L1) that binds to rhodium in a K3-P,O,P mode. The reactions catalyzed by this complex typically proceed at mild temperatures (room temperature to 70 °C) and occur with primary aminoalkenes lacking substituents on the alkyl chain that bias the system toward cyclization, with primary aminoalkenes containing chloride, ester, ether, enolizable ketone, nitrile, and unprotected alcohol functionality, and with primary aminoalkenes containing internal olefins. Mechanistic data imply that these reactions occur with a turnover-limiting step that is different from that of reactions catalyzed by late-transition-metal complexes of Pd, Pt, and Ir. This change in the turnover-limiting step and resulting high activity of the catalyst stem from favorable relative rates for protonolysis of the M-C bond to release the hydroamination product versus reversion of the aminoalkyl intermediate to regenerate the acyclic precursor. Probes of the origin of the reactivity of the rhodium complex of L1 imply that the aminophosphine groups lead to these favorable rates by effects beyond steric demands and simple electron donation to the metal center.
Complex-induced proximity effects: The effect of varying directing-group orientation on carbamate-directed lithiation reactions
Bertini Gross,Beak
, p. 315 - 321 (2007/10/03)
A series of selected bicyclic carbamates in which the range of accessible angles and distances between the carbonyl group and the proton removed in an α-lithiation reaction are structurally defined have been investigated. Oxazolidinones 7-10 undergo stereoselective lithiation-substitution reactions to provide cis-18-27 and cis-31-35 as the major diastereomers. Two series of competition experiments show that the conformationally restricted carbamates 7, 10, 11, and 15 undergo lithiation via complexes more efficiently than Boc amines 4-6. These results along with semiempirical calculations suggest that a small dihedral angle and a calculated distance of 2.78 A between the carbamate carbonyl oxygen and the proton to be removed are favorable for a carbamate-directed lithiation. A series of tin-lithium exchange experiments on cis- and trans-18 and (S)-39 indicate that the configurational stability of a carbamate-stabilized organolithium species may be enhanced by restrictive geometry.
Electroorganic chemistry 139. Electroreductive decyanation of nitriles and its application to synthesis of α-alkylamines
Shono, Tatsuya,Terauchi, Jun,Kitayama, Kenji,Takeshima, Yo-Ichiro,Masumura, Yoshihiro
, p. 8253 - 8262 (2007/10/02)
Electroreduction of nitriles gave the corresponding decyanated products when Zn was used as the material of cathode in aprotic solvent (DMF or MeCN) containing Et4NOTs as a supporting electrolyte. Alkylation of amines at the α-position was effectively achieved by cyanation of amines at the α-position, and α-alkylation of the resultant α-amino nitriles followed by the electroreductive decyanation.
