115549-32-1Relevant articles and documents
Palladium-catalyzed C-H activation of N-Allyl Imines: Regioselective allylic alkylations to deliver substituted aza-1,3-dienes
Trost, Barry M.,Mahapatra, Subham,Hansen, Martin
, p. 6032 - 6036 (2015)
A new mode of activation of an imine via a rare aza-substituted π-allyl complex is described. Palladium-catalyzed C(sp3)-H activation of the N-allyl imine and the subsequent nucleophilic attack by the α-alkyl cyanoester produced the 1-aza-1,3-d
Enantioselective construction of tetrasubstituted stereogenic carbons through bronsted base catalyzed michael reactions: α′-hydroxy enones as key enoate equivalent
Badiola, Eider,Fiser, Bla,Gmez-Bengoa, Enrique,Mielgo, Antonia,Olaizola, Iurre,Urruzuno, Iaki,Garca, Jess M.,Odriozola, Jos M.,Razkin, Jess,Oiarbide, Mikel,Palomo, Claudio
supporting information, p. 17869 - 17881 (2015/02/19)
Catalytic and asymmetric Michael reactions constitute very powerful tools for the construction of new C-C bonds in synthesis, but most of the reports claiming high selectivity are limited to some specific combinations of nucleophile/electrophile compound types, and only few successful methods deal with the generation of all-carbon quaternary stereocenters. A contribution to solve this gap is presented here based on chiral bifunctional Bronsted base (BB) catalysis and the use of α′-oxy enones as enabling Michael acceptors with ambivalent H-bond acceptor/donor character, a yet unreported design element for bidentate enoate equivalents. It is found that the Michael addition of a range of enolizable carbonyl compounds that have previously demonstrated challenging (i.e., α-substituted 2-oxindoles, cyanoesters, oxazolones, thiazolones, and azlactones) to α′-oxy enones can afford the corresponding tetrasubstituted carbon stereocenters in high diastereo- and enantioselectivity in the presence of standard BB catalysts. Experiments show that the α′-oxy ketone moiety plays a key role in the above realizations, as parallel reactions under identical conditions but using the parent α,β-unsaturated ketones or esters instead proceed sluggish and/or with poor stereoselectivity. A series of trivial chemical manipulations of the ketol moiety in adducts can produce the corresponding carboxy, aldehyde, and ketone compounds under very mild conditions, giving access to a variety of enantioenriched densely functionalized building blocks containing a fully substituted carbon stereocenter. A computational investigation to rationalize the mode of substrate activation and the reaction stereochemistry is also provided, and the proposed models are compared with related systems in the literature.
A highly enantio- and diastereoselective molybdenum-catalyzed asymmetric allylic alkylation of cyanoesters
Trost, Barry M.,Miller, John R.,Hoffman Jr., Christopher M.
supporting information; experimental part, p. 8165 - 8167 (2011/07/08)
An efficient molybdenum-catalyzed asymmetric allylic alkylation (Mo-AAA) of cyanoester nucleophiles is reported. A number of highly functionalized branched cyanoesters containing a quaternary carbon stereocenter with a vicinal tertiary stereocenter are obtained. This method generates a number of functionalized cyanoesters in excellent yield and chemoselectivity in good to excellent diastereoselectivity and enantioselectivity.
