Domino Alkene-Isomerization–Claisen Rearrangement Strategy to Substituted Allylsilanes
摘要:
A one-pot isomerization Claisen protocol has been developed for the synthesis of highly substituted allylsilanes. Monosilylated divinyl ethers can be isomerized using a cationic iridium(I) catalyst followed by a thermal Claisen rearrangement to provide the allylsilanes in excellent yields and diastereoselectivities.
Platinum catalysed hydrosilylation of propargylic alcohols
作者:Catherine A. McAdam、Mark G. McLaughlin、Adam J. S. Johnston、Jun Chen、Magnus W. Walter、Matthew J. Cook
DOI:10.1039/c3ob40496j
日期:——
A facile and user-friendly protocol has been developed for the selective synthesis of E-vinyl silanes derived from propargylicalcohols using a PtCl2/XPhos catalyst system. The reaction is generally high yielding and provides a single regioisomer at the β-position with E-alkene geometry. The reaction is extremely tolerant of functionality and has a wide scope of reactivity both in terms of alkynes
PtCl2/XPhos: A highly efficient and readily available catalyst for the hydrosilylation of propargylic alcohols
作者:Mark G. McLaughlin、Matthew J. Cook
DOI:10.1039/c1cc14433b
日期:——
A highly regioselectivehydrosilylation of propargylicalcohols has been developed using an in situ prepared PtCl(2)/XPhos catalyst system. The reaction is tolerant of many functional groups and exhibits excellent regio and geometric selectivity.
N-Heterocyclic carbene rhodium(<scp>i</scp>) complexes containing an axis of chirality: dynamics and catalysis
作者:Maria Cristina Cassani、Marta Anna Brucka、Cristina Femoni、Michele Mancinelli、Andrea Mazzanti、Rita Mazzoni、Gavino Solinas
DOI:10.1039/c3nj01620j
日期:——
Novel rhodium(i) complexes [RhCl(NBD)(NHC)] [NHC = 1-benzyl-3-R-imidazolin-2-ylidene; R = Me, Bz, Tr, tBu]: determination of the rotation barriers about the Rh-carbene and catalytic activity in the hydrosilylation of terminal alkynes.
新型铑(i)配合物 [RhCl(NBD)(NHC)] [NHC = 1-苄基-3-R-咪唑啉-2-基醇; R = 甲基,苯甲酰,三氟甲基,t丁基]:确定Rh-卡宾的旋转阻 barriers 以及在顺烯烃的氢硅烷化反应中的催化活性。
N-Heterocyclic Carbene-Amide Rhodium(I) Complexes: Structures, Dynamics, and Catalysis
hydrosilylation of terminal alkynes with HSiMe2Ph has been investigated with PhC≡CH, TolC≡CH, nBuC≡CH, Et3SiC≡CH, and (CPh2OH)C≡CH as substrates. The steric hindrance on the N-heterocyclic ligand and on the alkyne substrates affects conversion and selectivity: for the former the best results were achieved employing the less encumbered 3a catalyst with TolC≡CH, whereas by employing hindered alkynes such as Et3SiC≡CH
酰胺官能化的咪唑鎓盐[BocNHCH 2 CH 2 ImR ] X(R = Me,X = I,1a ; R =苄基,X = Br,1b ; R =三苯甲基,X = Cl,1c)带有越来越大的N-通过(2-咪唑-1-基-乙基)氨基甲酸叔丁酯的直接烷基化,高产率地制备烷基取代基。1c是结晶固体,其特征还在于X射线衍射。这些盐是合成铑(I)配合物[Rh(NBD)X(NHC)]的前体(NHC = 1-(2-NHBoc-乙基)-3-R-咪唑啉-2-亚基; X = Cl, R = Me(3a),R =苄基(3b),R =三苯甲基(3c); X = I,R = Me(4a))。所有的配合物都表现出绕金属碳烯键旋转受限的现象。然而,尽管为3a,b和4a计算的旋转势垒与实验值匹配,但出乎意料的是,对于3c而言,情况并非如此,因为3c的实验值等于化合物3b的实验值(58.6 kJ mol –1),并且相对于所计算的值较小(100
Domino Alkene-Isomerization–Claisen Rearrangement Strategy to Substituted Allylsilanes
作者:Mark G. McLaughlin、Matthew J. Cook
DOI:10.1021/jo202560g
日期:2012.2.17
A one-pot isomerization Claisen protocol has been developed for the synthesis of highly substituted allylsilanes. Monosilylated divinyl ethers can be isomerized using a cationic iridium(I) catalyst followed by a thermal Claisen rearrangement to provide the allylsilanes in excellent yields and diastereoselectivities.