Stereospecific stille-coupling reaction of (Z)-1,2-bis(trimethylstannyll)ethenes with hypervalent iodonium salts
摘要:
The Stille coupling of (Z)-1,2-bis(trimethylstannyl)ethenes with hypervalent iodonium salts (1 equiv) proceeded stereospecifically in the presence of PdCl2 (5 mol %) in DMF at room temperature to afford partially substituted (Z)-vinylstannanes under mild conditions. Alternatively, the use of 2 equivalents of hypervalent iodonium salts afforded tri-substituted alkenes. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
Seven phenyl-substituted vinylstannanes have been prepared. (Z)-beta-(trimethylstannyl)styrene, alpha-(trimethylstannyl)styrene, and 1,1-diphenyl-2-(trimethylstannyl)ethene were prepared by Grignard coupling between the appropriate phenyl-substituted vinyl bromide and chlorotrimethylstannane. (E)-beta-(Trimethylstannyl)styrene and (Z)-(trimethylstannyl)stilbene were prepared by AIBN catalyzed hydrostannation of the appropriate phenyl-substituted acetylene. (E)-(Trimethylstannyl)stilbene and methyl (E)-2-(trimethylstannyl)cinnamate were prepared by palladium(0) catalyzed hydrostannation of diphenylacetylene and methyl phenylpropiolate, respectively. Each compound was characterized by H-1, C-13, and Sn-119 NMR. Reactivity of each compound to protodestannylation was determined by spectrophotometric or H-1 NMR measurement of second order rate constants. The relative reactivity is interpreted on the basis of the electronic and steric effects of the phenyl substituents. The stereochemistry of destannylation resulted in retention of configuration for four of the compounds, consistent with an S(E)2 mechanism. However, methyl (E)-2-(trimethylstannyl)cinnamate gave an E/Z product ratio of essentially. This result is consistent with an allenol mechanism for protodestannylation of this compound.
Copper-catalyzed α-selective hydrostannylation of alkynes for the synthesis of branched alkenylstannanes
作者:H. Yoshida、A. Shinke、Y. Kawano、K. Takaki
DOI:10.1039/c5cc02720a
日期:——
A universal system for highly α-selective hydrostannylation of terminal alkynes has been developed by use of a distannane or a silylstannane as a stannylating reagent under copper catalysis.
Photochemical properties of cis- and trans-1,2-diphenylethenyl-trimethyltin(IV) and cis-1,2-diphenylpropenyltrimethyltin(IV) : organometallic derivatives of stilbene
作者:John M. Kelly、Raymond J. Trautman
DOI:10.1039/dt9840000909
日期:——
Upon direct u.v. irradiation in cyclohexane, benzene, alcohol, or chloroform solution, [Sn(CPhCHPh)Me3](1) undergoes cis-transisomerization about the olefin double bond as the only efficient reaction. No evidence has been found for either homolytic or heterolytic photocleavage of the Sn–C bond as a primary process. Unusually for stilbenes the photostationary state reached on irradiation (313 nm) is
Cis-Trans stereoselectivity in the Stannylmetallation of Diphenylacetylene
作者:Clark H. Cummins、Eva J. Gordon
DOI:10.1016/0040-4039(94)88263-0
日期:1994.10
Stereospecific cis- or trans- stannylcupration of diphenylacetylene can be obtained by temperature control during vinylcuprate hydrolysis.
可以通过在乙烯基铜酸盐水解过程中进行温度控制来获得二苯基乙炔的立体特异性顺式或反式苯乙烯基转移。
Sequential Reactions of Trimethylstannyl Anions with Vinyl Chlorides and Dichlorides by the S<sub>RN</sub>1 Mechanism Followed by Palladium-Catalyzed Cross-Coupling Processes
作者:Eduardo F. Córsico、Roberto A. Rossi
DOI:10.1021/jo049287z
日期:2004.9.1
good yields of vinylstannanes. Some of them react in the dark, and others need light stimulation to react. The fact that these reactions are inhibited by radical and radical anion traps shows that they occur by the SRN1mechanism. When the reaction takes place with 1,1-dichloro-1-alkenes, monosubstitution reduced products are formed in an E/Z mixture. The efficient synthesis of triarylolefins by Pd(0)-catalyzed
Phenyl-Substituted Vinylstannanes: Synthesis and Reactivity in Electrophilic Substitution Reactions
作者:John C. Cochran、Harmony K. Phillips、Samson Tom、Alexander R. Hurd、Brian S. Bronk
DOI:10.1021/om00015a031
日期:1994.3
Seven phenyl-substituted vinylstannanes have been prepared. (Z)-beta-(trimethylstannyl)styrene, alpha-(trimethylstannyl)styrene, and 1,1-diphenyl-2-(trimethylstannyl)ethene were prepared by Grignard coupling between the appropriate phenyl-substituted vinyl bromide and chlorotrimethylstannane. (E)-beta-(Trimethylstannyl)styrene and (Z)-(trimethylstannyl)stilbene were prepared by AIBN catalyzed hydrostannation of the appropriate phenyl-substituted acetylene. (E)-(Trimethylstannyl)stilbene and methyl (E)-2-(trimethylstannyl)cinnamate were prepared by palladium(0) catalyzed hydrostannation of diphenylacetylene and methyl phenylpropiolate, respectively. Each compound was characterized by H-1, C-13, and Sn-119 NMR. Reactivity of each compound to protodestannylation was determined by spectrophotometric or H-1 NMR measurement of second order rate constants. The relative reactivity is interpreted on the basis of the electronic and steric effects of the phenyl substituents. The stereochemistry of destannylation resulted in retention of configuration for four of the compounds, consistent with an S(E)2 mechanism. However, methyl (E)-2-(trimethylstannyl)cinnamate gave an E/Z product ratio of essentially. This result is consistent with an allenol mechanism for protodestannylation of this compound.