Asymmetric Aldol Reaction of Ketones with Alkenyl Trichloroacetates Catalyzed by Dibutyltin Dimethoxide and BINAP⋅Silver(I) Complex: Construction of a Chiral Tertiary Carbon Center
作者:Akira Yanagisawa、Yuuki Terajima、Kazuma Sugita、Kazuhiro Yoshida
DOI:10.1002/adsc.200900437
日期:2009.8
The reaction was found to be remarkably accelerated by the addition of a catalytic amount of a bidentate phosphine⋅silver(I) complex. Use of the BINAP⋅silver triflate (AgOTf) complex as the chiral co-catalyst resulted in the formation of optically active aldol products possessing a chiral tertiary carbon with up to 93% ee. This catalytic method was further applied to the asymmetric reaction of diketene
Methanol-Assisted Catalysis by Chiral Tin Methoxides: An Alternative Asymmetric Aldol Process
作者:Akira Yanagisawa、Tomoya Satou、Atsuto Izumiseki、Youichi Tanaka、Masahiko Miyagi、Takayoshi Arai、Kazuhiro Yoshida
DOI:10.1002/chem.200901822
日期:2009.11.2
Opening a tin of catalysts: A catalytic enantioselective aldol reaction of alkenyl trichloroacetates with aldehydes was achieved using a (S)‐BINOL‐derived chiral organotin(IV) dibromide possessing a 4‐tert‐butylphenyl group at the 3‐ and 3′‐position as a chiral pre‐catalyst in the presence of sodium methoxide and methanol (see scheme).
A catalyticasymmetricaldol reaction of alkenyl trichloroacetates with aldehydes was achieved using dibutyltin dimethoxide and BINAP · silver(I) complex as catalysts in a mixed solvent consisting of THF and MeOH. Various optically active β-hydroxy ketones were diastereoselectively obtained not only from aromatic and α,β-unsaturated aldehydes but also from an aliphatic aldehyde with good enantioselectivity
Enantioselective Nitroso Aldol Reaction Catalyzed by QuinoxP*·Silver(I) Complex and Tin Methoxide
作者:Akira Yanagisawa、Satoshi Takeshita、Youhei Izumi、Kazuhiro Yoshida
DOI:10.1021/ja910588w
日期:2010.4.21
A catalytic enantioselective O-nitroso aldol reaction of alkenyl trichloroacetates with nitrosoarenes was achieved using the (R,R)-t-Bu-QuinoxP*.AgOAc complex as the chiral catalyst and Bu(2)Sn(OMe)(2) as the achiral cocatalyst in the presence of methanol. Optically active alpha-aminooxy ketones with up to 99% ee were regioselectively obtained in high yields from various alkenyl trichloroacetates of
使用 (R,R)-t-Bu-QuinoxP*.AgOAc 配合物作为手性催化剂和 Bu(2)Sn(OMe)(2) 作为手性催化剂,实现了烯基三氯乙酸酯与亚硝基芳烃的催化对映选择性 O-亚硝基羟醛反应在甲醇存在下的非手性助催化剂。具有高达 99% ee 的光学活性 α-氨基氧基酮以高产率从环酮的各种烯基三氯乙酸酯中获得。
Thieme Chemistry Journal Awardees - Where
are They Now? Dibutyltin Dimethoxide Catalyzed <i>N</i>-Nitrosoaldol Reaction of
Alkenyl Trichloroacetate
Nitrosoaldol reaction between alkenyltrichloroacetates and nitrosobenzene has been achieved usingdibutyltindimethoxide as a catalyst, which is regenerated in the presence of methanol. The corresponding α-hydroxyamino ketones (N-adducts) have exclusively formed not only from cyclic alkenyltrichloroacetates but also from acyclic ones.