Conventional Lithium Bases as Unconventional Sources of Methyl Anion: Facile Me−Si and Me−C Bond Cleavage in RLi, R<sub>2</sub>NLi, and BR<sub>4</sub><sup>-</sup> by an Electrophilic Osmium Dihydride
作者:Dmitry V. Yandulov、John C. Huffman、Kenneth G. Caulton
DOI:10.1021/om0200104
日期:2002.9.1
and compete for the Os with, the original base, the unsaturated silicon species formed by Si−Me cleavage react with the remaining base by 1,2-addition of (N,C)-Li, forming intermediates that are also reactive by β-Me- transfer. A complex mixture of Os-free coproducts is obtained in both cases. The structural features of 1+ responsible for its unusual reactivity are discussed.
顺式,反式-Os(H)2(OTf)(NO)(P i Pr 3)2(1-OTf)和Os(H)2(NO)(P i Pr 3)的其他几种前体(1-X))2 +(1 +)与(ME反应3 Si)的2 NLi等,(ME 3 Si)的2 CHLi,锂2,2,6,6-四甲基(TMPLi)中,Me 3 SICH 2 Li和B(CH 2森达3)4 -由一个极不寻常的,轻便β-ME -转移,对于在非极性溶剂的前两个专属的反应途径。已经检验了一系列烷基锂和烷基酰胺和有机硼酸试剂以显示直接β-R的普遍发生“ -转移(R” = H,Me)的给OS电体,是用于完全选择性β-H -在β-我-,唯一(令人惊讶的)NpLi例外。的β-R“消除被排除作为净β-R的机构” -转移为两个代表性的RLi例R” = H,Me和单电子转移机理被证明是不起作用为tetraalkylborates。机理研究还揭示了Li在RLi和R 2 NL
An osmium hydrido methyl species via an unconventional methyl transfer
作者:Dmitry V. Yandulov、John C. Huffman、Kenneth G. Caulton
DOI:10.1039/b004484i
日期:——
Os(H)2(OTf)(NO)L2
(OTf=O3SCF3; L=PiPr3) reacts with Li(2,2,6,6-tetramethylpiperidide) (LiTMP) by methyl
transfer to give Os(H)2Me(NO)L2. The cyclic imine co-product is rapidly deprotonated by LiTMP to give an azaallyl anion that adds to Os(H)2(OTf)(NO)L2 to give Os(H)2(η1-C8H14N)(NO)L2, which was characterized by spectroscopic methods, independent synthesis and X-ray diffraction. Possible reasons for this CH3−
transfer ia C(sp3)–C(sp3) cleavage are discussed.
Os(H)2(OTf)(NO)L2(OTf=O3SCF3;L=PiPr3)与 Li(2,2,6,6-四甲基哌啶)(LiTMP)发生甲基转移反应,得到 Os(H)2Me(NO)L2。环状亚胺副产物迅速被 LiTMP 去质子化,生成氮杂烯丙基阴离子,该阴离子与 Os(H)2(OTf)(NO)L2 相加,生成 Os(H)2(η1-C8H14N)(NO)L2,并通过光谱方法、独立合成和 X 射线衍射对其进行了表征。本文讨论了这种 CH3- 转移 ia C(sp3)-C(sp3) 裂解的可能原因。
Asymmetric Synthesis of α-Alkylated Aldehydes using Terminal Epoxide-Derived Chiral Enamines
作者:David M. Hodgson、Naeem S. Kaka
DOI:10.1002/anie.200804369
日期:2008.12.8
Metalation of nonenolizable ketones and aldehydes by lithium dialkylamide bases
作者:Christopher S. Shiner、Andrew H. Berks、Allison M. Fisher
DOI:10.1021/ja00211a041
日期:1988.2.3
DNEPROVSKIJ, A. S.;MILTSOV, S. A., ZH. ORGAN. XIMII, 24,(1988) N0, S. 2037-2041