Triple Role of Phenylselenonyl Group Enabled a One-Pot Synthesis of 1,3-Oxazinan-2-ones From α-Isocyanoacetates, Phenyl Vinyl Selenones, and Water
摘要:
Reaction of alpha-substituted alpha-isocyanoacetates with phenyl vinyl selenones in the presence of a catalytic amount of base (DBU or Et3N, 0.05-0.1 equiv) followed by addition of p-toluenesulfonic acid (PTSA, 0.1-0.2 equiv) afforded 4,4,5-trisubstituted 1,3-oxazinan-2-ones in good to excellent yields. Enantiomerically enriched heterocycles can also be prepared using a Cinchona alkaloid-derived bifunctional organocatalyst for the Michael addition step. The phenylselenonyl group served as an activator for the Michael addition, a leaving group and a latent oxidant in this integrated reaction sequence.
Triple Role of Phenylselenonyl Group Enabled a One-Pot Synthesis of 1,3-Oxazinan-2-ones From α-Isocyanoacetates, Phenyl Vinyl Selenones, and Water
摘要:
Reaction of alpha-substituted alpha-isocyanoacetates with phenyl vinyl selenones in the presence of a catalytic amount of base (DBU or Et3N, 0.05-0.1 equiv) followed by addition of p-toluenesulfonic acid (PTSA, 0.1-0.2 equiv) afforded 4,4,5-trisubstituted 1,3-oxazinan-2-ones in good to excellent yields. Enantiomerically enriched heterocycles can also be prepared using a Cinchona alkaloid-derived bifunctional organocatalyst for the Michael addition step. The phenylselenonyl group served as an activator for the Michael addition, a leaving group and a latent oxidant in this integrated reaction sequence.
Catalytic Enantioselective Michael Addition of α-Aryl-α-Isocyanoacetates to Vinyl Selenone: Synthesis of α,α-Disubstituted α-Amino Acids and (+)- and (−)-Trigonoliimine A
作者:Thomas Buyck、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201306663
日期:2013.11.25
title reaction in the presence of the catalyst 1 afforded Michael adducts in excellent yields and enantioselectivities. The adducts were readily converted into α,α′‐disubstituted α‐aminoacids. The enantioselective total synthesis of both (+)‐ and (−)‐trigonoliimine A was accomplished using one of the Michael adducts derived from this methodology. M.S.=molecular sieves.
Silver-Catalyzed Asymmetric Desymmetrization of Cyclopentenediones via [3 + 2] Cycloaddition with α-Substituted Isocyanoacetates
作者:Jimil George、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.8b00590
日期:2018.4.20
A highly selective and practical asymmetric Ag(I) catalyst system has been developed for the [3 + 2] cycloaddition reactions between isocyanoacetates and cyclopentenediones. The current Ag(I) catalyst system tolerates moisture and air and readily utilizes class III solvents such as EtOAc and acetone. The development of on demand generation of an active chiral catalyst in the presence of isocyanides
Asymmetric Formal [3+2] Cycloaddition Reaction of Isocyanoesters to 2‐Oxobutenoate Esters by a Multifunctional Chiral Silver Catalyst
作者:Jin Song、Chang Guo、Peng‐Hao Chen、Jie Yu、Shi‐Wei Luo、Liu‐Zhu Gong
DOI:10.1002/chem.201100636
日期:2011.7.4
Silver‐standard selectivity! The first highly enantioselective formal [3+2] cycloaddition reaction of isocyanoesters with 2‐oxobutenoate esters catalyzed by a chiralsilver complex proceeded readily under the catalysis of a multifunctional chiralsilver complex in high yields and enantiometric excess (ee) values of up to 98 % (see scheme).
Regioselective Synthesis of Pyrroles from Alkyne-Isocyanide Click Reactions: An Angle Strain-Induced Bond Migration Approach
作者:Jimil George、Hun Young Kim、Kyungsoo Oh
DOI:10.1002/adsc.201601017
日期:2016.12.7
direct regioselective synthesis of highly functionalized pyrroles with two different electron‐withdrawing groups has been developed using an angle strain‐induced 1,2‐shift of an electron‐withdrawing group in 2H‐pyrroles. The preferential migration aptitude of an electron‐withdrawing group over alkyl and aryl groups is believed to be the result of the orbital overlap between the internal alkene and the
Chiral squaramides catalyzed diastereo- and enantioselective Michael addition of α-substituted isocyanoacetates to N-aryl maleimides
作者:Mei-Xin Zhao、Fei-Hu Ji、Deng-Ke Wei、Min Shi
DOI:10.1016/j.tet.2013.09.084
日期:2013.12
An efficient diastereo- and enantioselective Michael addition of α-substituted isocyanoacetates to N-aryl maleimidescatalyzed by quinine or cyclohexane-1,2-diamine derived squaramide catalysts has been disclosed, affording the corresponding adducts in good yields (up to 99%), high diastereoselectivities (up to >20:1 dr) and good to excellent enantioselectivities (up to 94% ee) under mild conditions