The borrowing-hydrogen (or hydrogen autotransfer) process, where the catalyst dehydrogenates a substrate and formally transfers the H atom to an unsaturated intermediate, is an atom-efficient and environmentally benign transformation. Described here is an example of an asymmetric borrowing-hydrogen cascade for the formal anti-Markovnikov hydroamination of allyl alcohols to synthesize optically enriched
Regio- and Enantioselective Iridium-Catalyzed Amination of Alkyl-Substituted Allylic Acetates with Secondary Amines
作者:Woo-Ok Jung、Minjin Yoo、Madyson M. Migliozzi、Jason R. Zbieg、Craig E. Stivala、Michael J. Krische
DOI:10.1021/acs.orglett.1c04135
日期:2022.1.14
Robust air-stable cyclometalated π-allyliridium C,O-benzoates modified by (S)-tol-BINAP catalyze the reaction of secondary aliphatic amines with racemic alkyl-substituted allylicacetates to furnish products of allylicamination with high levels of enantioselectivity. Complete branched regioselectivities were observed despite the formation of more highly substituted C–N bonds.
由 ( S )-tol-BINAP 改性的稳定的空气稳定环金属化 π-烯丙铱C , O-苯甲酸酯催化脂肪仲胺与外消旋烷基取代的烯丙乙酸酯的反应,提供具有高水平对映选择性的烯丙胺化产物。尽管形成了更高取代度的 C-N 键,但仍观察到完全支化的区域选择性。
Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective
Stereoselective Dehydroxyboration of Allylic Alcohols to Access (<i>E</i>)-Allylboronates by a Combination of C–OH Cleavage and Boron Transfer under Iron Catalysis
Iron-catalyzed direct SN2′ dehydroxyboration of allylic alcohols has been developed to access (E)-stereoselective allylboronates. Allylic alcohols with diverse structures and functional groups, especially derived from natural products, underwent smooth transformation. The six-membered ring transition state formed by allylic alcohols and iron–boron intermediate was indicated to be the key component
铁催化的烯丙醇直接 S N 2' 脱羟基硼酸已被开发用于获得 ( E )-立体选择性烯丙基硼酸酯。具有多种结构和官能团的烯丙醇,特别是来自天然产物的烯丙醇,经历了平稳的转变。由烯丙醇和铁-硼中间体形成的六元环过渡态被证明是参与硼基团转移、C-OH键活化和立体选择性控制的关键成分。
Direct, Enantioselective Iridium-Catalyzed Allylic Amination of Racemic Allylic Alcohols
作者:Marc Lafrance、Markus Roggen、Erick M. Carreira
DOI:10.1002/anie.201108287
日期:2012.4.2
The direct route: Iridium‐catalyzed direct conversion of branched allylicalcohols into enantioenriched branched primary allylic amines is highly regio‐ and enantioselective (see scheme; coe=cyclooctene).