Efficient Activation of Acetals, Aldehydes, and Imines toward Silylated Nucleophiles by the Combined Use of Catalytic Amounts of [Rh(COD)Cl]<sub>2</sub>and TMS-CN under Almost Neutral Conditions
In the presence of a catalytic amount of a transition metal compound such as [Rh(COD)Cl]2, Co(acac)2, or NiCl2, trimethylsilyl cyanide smoothly reacts with acetals to form α-methoxy carbonitriles in good yields. In the coexistence of catalytic amounts of [Rh(COD)Cl]2 and TMS-CN, silyl enol ethers or ketene silyl acetals react with acetals, aldehyes, or imines to yield the corresponding coupling products in good yields under almost neutral conditions.
One-Pot Silyl Ketene Acetal-Formation Mukaiyama-Mannich Additions to Imines Mediated by Trimethylsilyl Trifluoromethanesulfonate
作者:C. Wade Downey、Jared A. Ingersoll、Hadleigh M. Glist、Carolyn M. Dombrowski、Adam T. Barnett
DOI:10.1002/ejoc.201500958
日期:2015.11
the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base, thioesters are readily converted into silyl ketene acetals in situ and undergo Mukaiyama–Mannichaddition to N-phenylimines in one pot. The silyl triflate appears to play two roles, activating both the thioester and the imine. This process also works well when thioesters are replaced with amides, esters, or ketones. Products
A simple one-pot three-component reaction for preparation of secondary amines and amino esters mediated by lithium perchlorate
作者:Mohammad R Saidi、Najmoddin Azizi、Hasan Zali-Boinee
DOI:10.1016/s0040-4020(01)00636-6
日期:2001.7
of several secondaryamines and secondary amino esters are reported. Treatment of aldehydes (aliphatic or aromatic) with (trimethylsilyl)alkylamines, in the presence of 5 M lithium perchlorate in diethyl ether gives intermediate imines. Reaction of these intermediate imines with different nucleophiles and functionalized organozinc reagents, BrZnCH2COOR, produce a variety of secondaryamines and N-alkyl-
novel chiral Lewisbase catalysts were synthesized from L-serine and applied in the hydrosilylation of β-enamino esters, in which the optimal one promoted the reactions to afford a wide variety of β-amino esters in good yields with good enantioselectivities. It is noteworthy that several cyclic substrates were hydrosilylated under the optimal conditions to give the cyclic β-amino esters with high yields
A process for preparing organozinc halides in solvents, includes reacting a reactive halogen compound with zinc in one or more carboxylic esters. It is also possible to prepare keto, hydroxyl and amino compounds of organozinc halides obtained in a first step from a reactive halogen compound and zinc in one or more carboxylic esters, wherein the organozinc halide obtained is reacted in a second step with an electrophilic reaction partner and the reaction product of the second step is hydrolyzed in a third step.