34881-29-3Relevant articles and documents
Enantioselective addition of dimethylzinc to aldehydes catalyzed by a chiral perhydro-1,3-benzoxazine-based amino alcohol as ligand
Infante, Rebeca,Nieto, Javier,Andrs, Celia
, p. 1343 - 1348 (2012)
Dimethylzinc undergoes efficient enantioselective addition to a wide variety of aromatic and aliphatic aldehydes in the presence of a catalytic amount of a chiral perhydro-1,3-benzoxazine-based amino alcohol. Methyl carbinols are obtained in good yields and in enantiomeric excesses of 99% or more in the absence of any metal other than zinc. Georg Thieme Verlag Stuttgart · New York.
Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones
Vasilenko, Vladislav,Blasius, Clemens K.,Wadepohl, Hubert,Gade, Lutz H.
supporting information, p. 8393 - 8397 (2017/07/11)
A manganese alkyl complex containing a chiral bis(oxazolinyl-methylidene)isoindoline pincer ligand is a precatalyst for a catalytic system of unprecedented activity and selectivity in the enantioselective hydroboration of ketones, thus producing preparatively useful chiral alcohols in excellent yields with up to greater than 99 % ee. It is applicable for both aryl alkyl and dialkyl ketone reduction under mild reaction conditions (TOF >450 h?1 at ?40 °C). The earth-abundant base-metal catalyst operates at very low catalyst loadings (as low as 0.1 mol %) and with a high level of functional-group tolerance. There is evidence for the existence of two distinct mechanistic pathways for manganese-catalyzed hydride transfer and their role for enantiocontrol in the selectivity-determining step is presented.
Majority-Rules-Type Helical Poly(quinoxaline-2,3-diyl)s as Highly Efficient Chirality-Amplification Systems for Asymmetric Catalysis
Ke, Yuan-Zhen,Nagata, Yuuya,Yamada, Tetsuya,Suginome, Michinori
supporting information, p. 9333 - 9337 (2015/08/06)
A highly efficient majority-rules effect of poly(quinoxaline-2,3-diyl)s (PQXs) bearing 2-butoxymethyl chiral side chains at the 6- and 7-positions was established and attributed to large ΔGh values (0.22-0.41 kJmol-1), which are defined as the energy difference between P- and M-helical conformations per chiral unit. A PQX copolymer prepared from a monomer derived from (R)-2-octanol (23% ee) and a monomer bearing a PPh2 group adopted a single-handed helical structure (>99%) and could be used as a highly enantioselective chiral ligand in palladium-catalyzed asymmetric reactions (products formed with up to 94% ee), in which the enantioselectivity could be switched by solvent-dependent inversion of the helical PQX backbone. Bowing to the majority: Poly(quinoxaline-2,3-diyl) containing PPh2 groups and chiral side chains derived from (R)-2-octanol with 23% ee exhibited a single-handed-helical conformation and served as a highly enantioselective chiral ligand in palladium-catalyzed reactions (see scheme; se=screw-sense excess). The chirality of the polymer could be switched by a solvent effect to enable the synthesis of the enantiomeric products.
Asymmetric hydrogenation of 1-alkyl and 1-aryl vinyl benzoates: A broad scope procedure for the highly enantioselective synthesis of 1-substituted ethyl benzoates
Kleman, Patryk,Gonzlez-Liste, Pedro J.,Garca-Garrido, Sergio E.,Cadierno, Victorio,Pizzano, Antonio
, p. 4398 - 4408 (2015/02/05)
The enantioselective hydrogenation of enol esters of formula CH2=C(OBz)R with rhodium catalysts based on phosphine-phosphite ligands (P-OP) has been studied. The reaction has a broad scope, and it is suitable for the preparation of products pos
