Synthesis of Enantiopure 1-Aryl-1-butylamines and 1-Aryl-3-butenylamines by Diastereoselective Addition of Allylzinc Bromide to Imines Derived from (R)-Phenylglycine Amide
作者:Jan Dalmolen、Marcel van der Sluis、José W. Nieuwenhuijzen、Auke Meetsma、Ben de Lange、Bernard Kaptein、Richard M. Kellogg、Quirinus B. Broxterman
DOI:10.1002/ejoc.200300662
日期:2004.4
The highlydiastereoselective addition of allylzinc bromide to imines derivedfrom (R)-phenylglycine amide is reported. Homoallylamines with high enantiomeric purity are obtained from the adducts in three steps on removal of the chiralauxiliary by means of a nonreductive protocol. Removal of the auxiliary by hydrogenation leads to the saturated amines, also in high enantiomeric purity. [reaction: see
sphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the arylhalide is remarkable; substituents such as fluoro, methyl, methoxy
通过使用[PdCl(C 3 H 5)] 2 /顺式,顺式,顺式-1,2,3,4-四(二苯基膦甲基)环戊烷作为催化剂,一系列芳基溴化物和氯化物进行铃木交叉偶联与烷基硼酸的收率很好。几个烷基取代基,例如乙基,正丁基,n已经成功地使用了烷基硼酸上的-辛基,异丁基或2,2-二甲基丙基。芳基卤对官能团的耐受性显着;可以容忍诸如氟,甲基,甲氧基,乙酰基,甲酰基,苯甲酰基,硝基或腈之类的取代基。此外,该催化剂即使在位阻芳基溴的反应中也可以低负荷使用。
Sequential Difunctionalization of 2-Iodobiphenyls by Exploiting the Reactivities of a Palladacycle and an Acyclic Arylpalladium Species
A novel sequential difunctionalization reaction of 2-iodobiphenyl has been developed by exploiting the distinct reactivities of a palladacycle and an acyclic arylpalladium species. In this tandem reaction, an in situ formed dibenzopalladacyclopentadiene reacts selectively with an alkyl halide, after which the thus formed acyclic arylpalladium species selectively undergoes a Heck reaction with an alkene
Phenyl-substituted N,N-dimethylanilines, synthesized by Suzuki coupling reactions in good yields, are transformed to their corresponding arylic carbanions by reductive C-N cleavage with lithium at room temperature. These carbanions react with various electrophiles affording the corresponding ipso-substituted products with absolute regioselectivity.
Organogelation enables fast organolithium cross-coupling reactions in air
作者:Paco Visser、Ben L. Feringa
DOI:10.1039/d3cc00756a
日期:——
on palladium-catalysed cross-coupling reactions using organolithium reagents has seen major breakthroughs in the past decade. However, the use of inert conditions, as well as slow addition of the organolithium species, is generally required. Here we describe the Pd-catalysed cross-coupling of C36H74-gelated organolithium reagents with aryl bromides. The reaction proceeds in 5 min at room temperature
在过去十年中,基于有机锂试剂的钯催化交叉偶联反应的 C-C 键形成取得了重大突破。然而,通常需要使用惰性条件以及缓慢添加有机锂物质。在这里,我们描述了 Pd 催化的 C 36 H 74凝胶化有机锂试剂与芳基溴化物的交叉偶联。反应在室温下进行 5 分钟,同时消除了以前需要的缓慢添加,并严格使用惰性气氛。至关重要的是,有机锂凝胶的使用方便了处理,并极大地提高了过程安全性,不需要任何特殊安全预防措施的克级转化就说明了这一点。