CoII/Box‐catalyzed [Box=bis(oxazoline)] enantioselective addition of potassium allyltrifluoroborate to cyclic ketimines was developed, providing the corresponding chiral α‐tertiary amines in high yields and with good enantioselectivity values. Alkoxycarbonyl‐ and alkyl‐substituted saccharin‐derived ketimines are suitable substrates for this allylation reaction. The product can be converted to complex molecules
开发了Co II / Box催化的[Box =双(恶唑啉)]烯丙基三氟硼酸钾对环酮亚胺的对映选择性加成,提供了高收率和良好对映选择性值的相应手性α-叔胺。烷氧羰基和烷基取代的糖精衍生的酮亚胺是该烯丙基化反应的合适底物。该产品可以通过几个简单的步骤转化为复杂的分子,包括MK-0371的前体,它是一种驱动蛋白纺锤体蛋白抑制剂。另外,该催化体系显示出强烈的正非线性效应。
Organophotoredox‐Catalyzed Decarboxylative N‐Alkylation of Sulfonamides
and transitionmetal-free conditions, a series of functionalized N-alkylated sulfonamides were prepared. This protocol also enabled the functionalization of pharmaceutical drugs bearing a sulfonamide or carboxylic acid moiety. This radical-mediated process allowed the assembly of three components including sulfonamides, redox active esters, and alkenes to yield complex sulfonamides in a one-pot manner
Bifunctional Amino Sulfonohydrazide Catalyzed Direct Asymmetric Mannich Reaction of Cyclic Ketimines with Ketones: Highly Diastereo- and Enantioselective Construction of Quaternary Carbon Stereocenters
sulfonohydrazide which contains multiple sites for hydrogen bonding with substrates was found to enhance reactivity and enantioselectivity in the direct asymmetric Mannich reaction of N-sulfonyl cyclic ketimines with ketones. In this efficient transformation, not only methyl ketones but also cyclic ketones can be employed to provide a general methodology to construct tetrasubstituted α-amino ester in a stereoselective
cyclic N-sulfonyl ketimines was developed, providing the corresponding chiral α-tertiary amines with up to 98% ee. The method tolerates some variations in cyclic N-sulfonyl ketimine and alkyne scope. These products could be used in several transformations, in particular, the products of 6-membered cyclic N-sulfonyl ketimines could be easily converted to linear chiral α-tertiary amines. This asymmetric
Copper (II)/RuPHOX-Catalyzed Enantioselective Mannich-Type Reaction of Glycine Schiff Bases with Cyclic Ketimines
作者:Qihang Shao、Liang Wu、Jianzhong Chen、Ilya D. Gridnev、Guoqiang Yang、Fang Xie、Wanbin Zhang
DOI:10.1002/adsc.201800850
日期:2018.12.3
enantioselective Mannich‐type reaction of glycine Schiff bases with cyclic ketimines was developed, affording chiral α,ß‐diaminoacidderivatives in good yields with moderate to good ee and dr values. This provides an efficient methodology for furnishing chiral Cβ‐tetrasubstituted α,β‐diaminoacid precursors. The catalytic system is compatible with a series of substrates. In addition, an interesting nonlinear