Enantioselective Conjunctive Cross-Coupling of Bis(alkenyl)borates: A General Synthesis of Chiral Allylboron Reagents
作者:Emma K. Edelstein、Sheila Namirembe、James P. Morken
DOI:10.1021/jacs.7b01774
日期:2017.4.12
conjunctive cross-coupling is used for the synthesis of enantioenriched allylboron reagents. This reaction employs nonsymmetric bis(alkenyl)borates as substrates and appears to occur by a mechanism that involves selective activation of the less substituted alkene followed by migration of the more substituted alkene during the course of a Pd-induced metalate rearrangement.
A non-enzymatic acetyl transfer-based kinetic resolution of primary allylic amines is reported. The process involves the use of (1S,2S)-1 in conjunction with a supported ammonium salt and affords the corresponding enantio-enriched N-acetylated allylic amines with unprecedented levels of selectivity (s-factors up to 34).
Application of LB-Phos·HBF4 in the Suzuki Coupling Reaction of 2-Bromoalken-3-ols with Alkylboronic Acids
作者:Binjie Guo、Chunling Fu、Shengming Ma
DOI:10.1002/ejoc.201200350
日期:2012.7
LB-Phos·HBF4 was used in the Suzukicouplingreaction of 2-bromoalken-3-ols with alkylboronicacids to give the coupling products in moderate to good yields. Substituents such as benzyl, phenyl, allyl, and alkyl are tolerated at the 1- and 3-positions of the 2-bromoalken-3-ols. The reactions of both primary and secondary alkylboronicacids proceed smoothly.
An Efficient Approach to 2-Bromoalken-3-ols by Regioselective Bromohydroxylation Reaction of Simple Allenes with NBS
作者:Wangqing Kong、Binjie Guo、Chunling Fu、Shengming Ma
DOI:10.1002/ejoc.201001676
日期:2011.4
A regioselectivebromohydroxylationreaction of simpleallenes affording 2-bromoalken-3-ols in moderate-to-good yields has been developed by using NBS as the electrophilic reagent in a mixture of 1,4-dioxane/H 2 O (1:1) at room temperature. Through this study it has been concluded that the regioselectivity is determined by various factors including steric and electronic effects of the substituents
通过在 1,4-二恶烷/H 2 O (1:1) 混合物中使用 NBS 作为亲电试剂,开发了简单丙二烯的区域选择性溴羟基化反应,以中等至良好的收率提供 2-bromoalken-3-ols在室温下。通过这项研究得出的结论是,区域选择性由各种因素决定,包括丙二烯部分取代基的空间和电子效应。
A catalytic asymmetric bromocyclization of trisubstituted olefinic amides that uses a C(2)-symmetric mannitol-derived cyclic selenium catalyst and a stoichiometric amount of N-bromophthalimide is reported. The resulting enantioenriched pyrrolidine products, which contain two stereogenic centers, can undergo rearrangement to yield 2,3-disubstituted piperidines with excellent diastereoselectivity and