Magnesium Catalysis of Imine Hydroboration

被引:122
作者
Arrowsmith, Merle [1 ]
Hill, Michael S. [1 ]
Kociok-Koehn, Gabriele [1 ]
机构
[1] Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England
基金
英国工程与自然科学研究理事会;
关键词
homogeneous catalysis; hydroboration; imines; magnesium; main group elements; CHIRAL TITANOCENE CATALYST; ASYMMETRIC HYDROGENATION; INTERMOLECULAR HYDROAMINATION; CARBONYL-COMPOUNDS; REDUCING AGENT; HYDROSILYLATION; REDUCTION; COMPLEXES; CALCIUM; KETONES;
D O I
10.1002/chem.201203190
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The -diketiminato magnesium alkyl complex [LMgnBu] (L=CH{CMe(NDipp)}2, Dipp=diisopropylphenyl) is shown to be a highly effective precatalyst for the hydroboration of alkyl and aryl substituted aldimines and ketimines with pinacol borane (HBpin). Catalysis is proposed to occur through a sequence of MgN/BH metathesis and rate-determining MgH/NC insertion steps, a proposal strongly supported by stoichiometric studies and kinetic analysis. The reactions are observed to proceed through the intermediacy of well-defined magnesium amides, two examples of which have been isolated and structurally characterized. Mechanistic investigations suggest that the catalytic rate-determining process occurs at an isolated magnesium center and requires the presence of two molecules of the imine substrate for effective turnover. This latter observation is rationalized as a requirement for the secondary substrate molecule to displace HBpin from the coordination sphere of the catalytic magnesium center.
引用
收藏
页码:2776 / 2783
页数:8
相关论文
共 67 条
[21]   Organocatalytic asymmetric transfer hydrogenation of imines [J].
de Vries, Johannes G. ;
Mrsic, Natasa .
CATALYSIS SCIENCE & TECHNOLOGY, 2011, 1 (05) :727-735
[22]   Transition metal-catalyzed hydrosilylation of carbonyl compounds and imines.: A review [J].
Diez-Gonzalez, Silvia ;
Nolan, Steven P. .
ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL, 2007, 39 (06) :523-+
[23]   Low coordinate magnesium chemistry supported by a bulky β-diketiminate ligand [J].
Dove, AP ;
Gibson, VC ;
Hormnirun, P ;
Marshall, EL ;
Segal, JA ;
White, AJP ;
Williams, DJ .
DALTON TRANSACTIONS, 2003, (15) :3088-3097
[24]   Artificial Transfer Hydrogenases for the Enantioselective Reduction of Cyclic Imines [J].
Duerrenberger, Marc ;
Heinisch, Tillmann ;
Wilson, Yvonne M. ;
Rossel, Thibaud ;
Nogueira, Elisa ;
Knoerr, Livia ;
Mutschler, Annette ;
Kersten, Karoline ;
Zimbron, Malcolm Jeremy ;
Pierron, Julien ;
Schirmer, Tilman ;
Ward, Thomas R. .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2011, 50 (13) :3026-3029
[25]  
Durrenberger M., 2011, ANGEW CHEMIE, V123, P3082
[26]   Taking the F out of FLP: Simple Lewis Acid-Base Pairs for Mild Reductions with Neutral Boranes via Borenium Ion Catalysis [J].
Eisenberger, Patrick ;
Bailey, Adrian M. ;
Crudden, Cathleen M. .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2012, 134 (42) :17384-17387
[27]   Mechanistic analysis of the transition metal-catalyzed hydrogenation of imines and functionalized enamines [J].
Fabrello, Amandine ;
Bachelier, Alice ;
Urrutigoity, Martine ;
Kalck, Philippe .
COORDINATION CHEMISTRY REVIEWS, 2010, 254 (3-4) :273-287
[28]   Metal-Free Transfer Hydrogenation Catalysis by B(C6F5)3 [J].
Farrell, Jeffrey M. ;
Heiden, Zachariah M. ;
Stephan, Douglas W. .
ORGANOMETALLICS, 2011, 30 (17) :4497-4500
[29]  
Figlus M., 2010, RECOVERABLE CATALYST
[30]   Highlights of Transition Metal-Catalyzed Asymmetric Hydrogenation of Imines [J].
Fleury-Bregeot, Nicolas ;
de la Fuente, Veronica ;
Castillon, Sergio ;
Claver, Carmen .
CHEMCATCHEM, 2010, 2 (11) :1346-1371