Alkenes from Terminal Epoxides Using Lithium 2,2,6,6-Tetramethylpiperidide and Organolithiums or Grignard Reagents
作者:David M. Hodgson、Matthew J. Fleming、Steven J. Stanway
DOI:10.1021/ja045513a
日期:2004.10.1
alkenes, dienes, and allylsilanes) are efficiently prepared by alpha-deprotonation of terminal epoxides using lithium 2,2,6,6-tetramethylpiperidide, followed by in situ trapping with organolithiums or Grignardreagents.
The Reactivity of Epoxides with Lithium 2,2,6,6-Tetramethylpiperidide in Combination with Organolithiums or Grignard Reagents
作者:David M. Hodgson、Matthew J. Fleming、Steven J. Stanway
DOI:10.1021/jo070291v
日期:2007.6.1
2-disubstituted epoxides in the presence of LTMP to generate alkenes in a completely regio- and highlystereoselective manner. Arylated alkenes, dienes, allylsilanes, and enynes are accessed using this procedure. The methodology is applied in the synthesis of the roller leaf moth pheromone, (3E,5Z)-dodecadienyl acetate. The corresponding reaction without LTMP has also been examined, and a study using deuterated
作者:Michael R. Buchmeiser、Suman Sen、Christina Lienert、Laura Widmann、Roman Schowner、Katharina Herz、Philipp Hauser、Wolfgang Frey、Dongren Wang
DOI:10.1002/cctc.201600624
日期:2016.8.22
Mo–imido alkylidene N‐heterocyclic carbene (NHC) complexes (1–15) and of the first complexes containing bidentate NHC‐phenolate ligands (16–18) are reported. Mo(N‐2,6‐Me2‐C6H3)((1‐R‐phenethyl)‐3‐mesitylimidazolidin‐2‐ylidene)(CHR)(OTf)2 (R=CMe2Ph, 1) is the first enantiomericallypure Mo–imido alkylidene NHC catalyst. With [Mo(N‐2,6‐Me2‐C6H3)(IMes)(CHR)(CH3CN)(OTf)(CH3CN)+ B(ArF)4−] (7), turnover numbers
一系列的Mo-酰亚胺的亚烷基N-杂环卡宾(NHC)络合物(的合成和单晶X射线结构1 - 15和含二齿NHC-酚配体的第一复合物的()16 - 18)的报告。Mo(N ‐2,6-Me 2 ‐C 6 H 3)((1- R ‐苯乙基)‐3‐甲酰亚胺咪唑啉‐2亚烷基)(CHR)(OTf)2(R = CMe 2 Ph,1)为第一个对映体纯的Mo-酰亚胺亚烷基NHC催化剂。与[Mo(N ‐2,6‐Me 2 ‐C 6 H 3)(IMes)(CHR)(CH3 CN)(OTf)(CH 3 CN)+ B(Ar F)4 − ](7),在1-辛烯和1-壬烯的同质复分解(HM)中,营业额高达545 000 E)。使用7和1-壬烯,可以确定8860 min -1的周转频率(TOF 4 min)。生产率和E / Z选择性与催化剂结构相关。对于1,Mo(N - 3,5 -Me 2 -C 6 H 3)(IMesH 2)(CHR)(OTf)2(9)和Mo(N
Stereospecific substituted alkene synthesis by organo lithium reductive alkylation of epoxides
作者:Eric Doris、Luc Dechoux、Charles Mioskowski
DOI:10.1016/0040-4039(94)80017-0
日期:1994.10
Stereospecifically alkylated olefins were synthesized in good yields by reaction of various epoxides with organolithium reagents with concommitant introduction of the alkyl group.
Halogen-magnesium exchange of various aryl halides is achieved with a magnesium ate complex at low temperatures; Tributylmagnesate ((Bu3MgLi)-Bu-n) induces facile iodine-magnesium exchange at -78 degreesC. Dibutylisopropylmagnesate ((PrBu2MgLi)-Pr-i-Bu-n) is more reactive than (Bu3MgLi)-Bu-n, and this reagent accomplishes selective bromine-magnesium exchange at -78 degreesC. This procedure is utilized for the preparation of various polyfunctionalized arylmagnesium species. The exchange of alkenyl halides using this method proceeds with retention of configuration of the double bond.