已经开发了一种实用且有用的催化对映选择性方法,用于从可商购的芳族酮和芳基或杂芳基溴化物开始合成叔二芳基和芳基杂芳基甲醇。在该方法中,通过用n BuLi锂化从溴化物中原位生成有机钛试剂,然后用ClTi(O i Pr)3对所得的有机锂进行金属转移。在(R)-3-(3,5-双三氟甲基苯基)-1,1'-联-2-萘酚(BTFP-BINOL)以高对映选择性和高收率提供了相应的叔醇。反应也可以从呋喃和2-噻吩基锂开始。该方法操作简单,可在10 mmol规模下进行而没有任何困难。
Extremely Efficient Cross-Coupling of Benzylic Halides with Aryltitanium Tris(isopropoxide) Catalyzed by Low Loadings of a Simple Palladium(II) Acetate/Tris(p-tolyl)phosphine System
Highly efficient coupling reactions of benzylic bromides or chlorides with aryltitaniumtris(isopropoxide) [ArTi(O‐i‐Pr)3] catalyzed by a simplepalladium(II) acetate/tris(p‐tolyl)phosphine [Pd(OAc)2/ P(p‐tolyl)3] system are reported. The coupling reactions proceed in general at room temperature employing low catalyst loadings of 0.02 to 0.2 mol%, affording coupling products in excellent yields of
A general palladium-catalyzed cross-coupling of aryl fluorides and organotitanium (IV) reagents
作者:Xiao-Yun He
DOI:10.1007/s00706-021-02796-6
日期:2021.7
Pd(OAc)2/1-[2-(di-tert-butylphosphanyl)phenyl]-4-methoxy-piperidine was demonstrated to effectively catalyze cross-coupling of aryl fluoride and aryl(alkyl) titanium reagent. Both electron-deficient and electron-rich aryl fluoride can react effectively with nucleophile and provide extensive functional groups tolerance. 2-Arylated product was realized by selective activation of the C–F bond. Graphic
Rhodium-Catalyzed Asymmetric 1,4-Addition of Aryltitanium Reagents Generating Chiral Titanium Enolates: Isolation as Silyl Enol Ethers
作者:Tamio Hayashi、Norihito Tokunaga、Kazuhiro Yoshida、Jin Wook Han
DOI:10.1021/ja027663w
日期:2002.10.1
triisopropoxide (ArTi(OPr-i )3) to alpha,beta-unsaturated ketones proceeded with high enantioselectivity (94-99.8% ee) in the presence of 3 mol % of [Rh(OH)((S )-binap)]2 in THF at 20 degrees C to give high yields of the titanium enolates as 1,4-addition products. The titanium enolates were converted into silyl enol ethers by treatment with chlorotrimethylsilane and lithium isopropoxide.
Selectivities in the Reactions of Alkyl-, Aryl- and Heterosubstituted Organotitanium Compounds Preliminary Communication
作者:Beat Weidmann、Leo Widler、Alan G. Olivero、Christopher D. Maycock、Dieter Seebach
DOI:10.1002/hlca.19810640136
日期:1981.2.4
Solutions of the title compounds R-Ti(OR′)3 (1) are generally available from organolithium (or magnesium) derivatives according to equation 1. It is shown (Table 1) that some heterosubstitutedorganotitaniumcompounds are more stable thermally than their lithium counterparts. The reagents 1 are highly selective carbonylophiles (Tables 1 and 2), their reactivity can be modified by variation of the R′O-group
Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
作者:Chuan Wu、Qing-Han Li
DOI:10.1016/j.tet.2021.132370
日期:2021.9
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides