Hydroxymethylation beyond Carbonylation: Enantioselective Iridium-Catalyzed Reductive Coupling of Formaldehyde with Allylic Acetates via Enantiotopic π-Facial Discrimination
作者:Victoria J. Garza、Michael J. Krische
DOI:10.1021/jacs.6b01078
日期:2016.3.23
2-propanol-mediated reductive coupling of branched allylic acetates 1a-1o with formaldehyde to form primary homoallylic alcohols 2a-2o with excellent control of regio- and enantioselectivity. These processes, which rely on enantiotopic π-facial discrimination of σ-allyliridium intermediates, represent the first examples of enantioselective formaldehyde C-C coupling beyond aldol addition.
SEGPHOS 修饰的手性铱配合物可催化 2-丙醇介导的支链烯丙乙酸酯 1a-1o 与甲醛的还原偶联,形成高烯丙醇 2a-2o,并具有出色的区域选择性和对映选择性控制。这些过程依赖于 σ-烯丙基铱中间体的对映体 π-面辨别,代表了羟醛加成以外的对映选择性甲醛 CC 偶联的第一个例子。
Ligand dependence of molybdenum-catalyzed alkylations. Molybdenum-isonitrile complexes as a new class of highly reactive alkylation catalysts
作者:Barry M. Trost、Craig A. Merlic
DOI:10.1021/ja00182a018
日期:1990.12
generates the most effective molybdenum catalysts known to date. The reactive catalyst proved to be Mo(RNC) 4 (CO) 2 . With this new catalyst, a much broader range of substrates can be employed including many that failed or reacted very poorly by using molybdenumhexacarbonyl. The regioselectivity also differs from that obtained with molybdenumhexacarbonyl. The stereochemistry of the reaction proceeds with
Catalytic compositions and methods for asymmetric allylic alkylation
申请人:——
公开号:US20020198383A1
公开(公告)日:2002-12-26
Complexes of a selected class of chiral ligands with molybdenum, tungsten or chromium, preferably molybdenum, are effective as catalysts in highly enantioselective and regioselective alkylation of allylic substrates.
Enantioselective Allylic Alkylation with 4-Alkyl-1,4-dihydro-pyridines Enabled by Photoredox/Palladium Cocatalysis
作者:Hong-Hao Zhang、Jia-Jia Zhao、Shouyun Yu
DOI:10.1021/jacs.8b10766
日期:2018.12.12
alkylation has been achieved enabled by the merger of photoredox and palladiumcatalysis. In this dual catalytic process, alkyl radicals generated from 4-alkyl-1,4-dihydropyridines act as the coupling partners of the π-allyl palladium complexes. The generality of this method has been illustrated through the reaction of a variety of allylesters with 4-alkyl-1,4-dihydropyridines. This mechanistically novel
Enantioselective α-Allylation of Anilines Enabled by a Combined Palladium and Photoredox Catalytic System
作者:Hong-Hao Zhang、Jia-Jia Zhao、Shouyun Yu
DOI:10.1021/acscatal.0c00871
日期:2020.4.17
branch-regioselective α-allylation of N-methyl anilines under dual palladium/photoredoxcatalysis is described. Readily available N-methyl anilines are used as formal “hard” alkyl nucleophiles without preactivation. Acetic acid is the only side product, which leads to a high atom economy of this reaction. This protocol shows good functional group tolerance and broad scope. A range of chiral homoallylic amines were