Categories: C-Cl Bond Formation >
Synthesis of vinyl chlorides
| Related: |
|
Recent Literature

Using triethylamine as catalyst in Hunsdiecker reactions with N-halosuccinimides
as Br+ or I+ source, cinnamic acids, and propiolic acids are
converted to the corresponding α-halostyrenes and 1-halo-1-alkynes in good isolated yields within 1-5 min.
J. Prakash, S. Roy, J. Org. Chem.,
2002, 67, 7861-7864.

The reaction of aromatic ketones with bis(trichloromethyl) carbonate afforded
aryl-(Z)-vinyl chlorides in the presence of scandium triflate, DMF, and
benzoyl chloride as catalysts. A plausible addition-elimination mechanism is
proposed. This catalytic method enables a green route to aryl-(Z)-vinyl
chlorides.
W. Su, C. Jin, Org. Lett., 2007,
9, 993-996.

α-Bromo- or α-chloro-α,β-unsaturated carbonyl compounds were prepared in good
yields by addition of hydrobromic acid or hydrochloric acid to α,β-unsaturated
carbonyl compounds in the presence of Oxone in CH2Cl2
followed by treatment of the resulting dihalides with Et3N.
K.-M. Kim, I.-H. Park, Synthesis,
2004, 2641-2644.

Aryl allylic alcohols are converted to halogenated unsaturated ketones or
allylic halides under Moffatt-Swern Conditions using excess DMSO and oxalyl
chloride or oxalyl bromide. Electron-poor aromatic rings favor formation of the
halogenated ketone, while electron-donating substituents in the ortho or
para
positions favor formation of the allylic halide.
J. Yin, C. E. Gallis, J. D. Chisholm, J. Org. Chem.,
2007, 72, 7054-7057.

C-O bond cleavage of lithium alkoxides occurs readily at room temperature in the
presence of titanium(IV) halides. Capture of the resultant carbocation by
alkynes provides an efficient route to trisubstituted (E)-alkenyl halides
with high stereoselectivity.
M.-L. Yao, T. R. Quick, Z. Wu, M. P. Quinn, G. W. Kabalka, Org. Lett., 2009,
11, 2647-2649.

2-Alkynyl esters are stereo- and regioselectively converted to E-β-chloro-α-iodo-α,β-unsaturated
esters by exposure to Bu4NI in refluxing dichloroethane.
Single-isomer tetrasubstituted olefins bearing four different carbon
substituents are then synthesized by sequential palladium-catalyzed coupling
reactions.
A. B. Lemay, K. S. Vulic, W. W. Ogilvie, J. Org. Chem., 2006,
71, 3615-3618.

Various bis-activated cyclopropenes undergo highly stereoselective ring-opening
reactions to produce multisubstituted alkenyl halides in the presence of
stoichiometric magnesium halides. Trapping of the magnesium enolate
intermediates in situ allows the synthesis of highly functionalized compounds.
Y. Wang, H. W. Lam, J. Org. Chem., 2009,
74, 1353-1355.

Poly{[4-(hydroxy)(tosyloxy)iodo]styrene} was efficient in the halotosyloxylation
reaction of alkynes with iodine or NBS or NCS. The polymer reagent could be
regenerated and reused.
J.-M. Chen, X. Huang, Synthesis, 2004,
1557-1558.

