Categories: C=C Bond Formation >
Synthesis of allenes
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Recent Literature
Treatment of 1,1-dichloroalk-1-enes with Cp2Ti[P(OEt)3]2
produced organotitanium species, which reacted with aldehydes and ketones to
afford allenes.
T. Shono, K. Ito, A. Tsubouchi, T. Takeda, Org. Biomol. Chem., 2005, 3, 2914-2916.
Lithium alkoxides of β-silylallylic alcohols underwent the Peterson elimination
in DMF to give allenes. A one pot process for a Peterson allenation reaction of
carbonyl compounds using (Z)-(1-lithio-1-alkenyl)trimethylsilanes is described.
A. Tsubouchi, T. Kira, T. Takeda, Synlett, 2006,
2577-2580.
A. Tsubouchi, T. Kira, T. Takeda, Synlett, 2006,
2577-2580.
An efficient protocol for the palladium-catalyzed Heck alkynylation using XPhos
as ligand and Cs2CO3 as the base, couples a wide range of
functionalized terminal alkynes and substituted benzyl chlorides. An excess
amount of base and higher reaction temperatures allows the synthesis of allenes
in a one-pot procedure.
C. H. Larsen, K. W. Anderson, R. E. Tundel, S. L. Buchwald, Synlett, 2006,
2941-2946.
Enantiomerically enriched 2,3-allenols were prepared by the CuBr-mediated
homologation of the relatively easily available optically active terminal
propargylic alcohols with paraformaldehyde in the presence of
diisopropylamine.
S. Ma, H. Hou, S. Zhao, G. Wang, Synthesis, 2002, 1643-1645.
In the presence of Ph3P and a catalytic amount of Fe(TCP)Cl, ketenes
react with EDA to give allenes in high yields under neutral conditions. By
employing a chiral phosphine, allenes could be synthesized with high
enantioselectivity in good yields.
C.-Y. Li, X.-B. Wang, X.-L. Sun, Y. Tang, J.-C. Zheng, Z.-H. Xu, Y.-G. Zhou,
L.-X. Dai, J. Am. Chem. Soc., 2007,
129, 1494-1495.
C.-Y. Li, X.-B. Wang, X.-L. Sun, Y. Tang, J.-C. Zheng, Z.-H. Xu, Y.-G. Zhou,
L.-X. Dai, J. Am. Chem. Soc., 2007,
129, 1494-1495.
The facile iodolactonisation of ethyl 2,3-allenoates with I2 in aqueous MeCN
gave 4-iodofuran-2(5H)-ones in moderate to
high yields.
C. Fu, S. Ma, Eur. J. Org. Chem., 2005,
3942-3945.
Lithiation of 1-iodo-1,3-dienyl
phosphine oxides and subsequent Wittig-Horner reaction with aldehydes gives
vinyl allenes in high yields. The preparation of the 1-iodo-1,3-dienyl phosphine oxides
is described. This multi-step sequence allows the synthesis of vinyl allenes
from two different alkynes and one aldehyde.
Z. Xi, W.-X. Zhang, Z. Song, W. Zheng, F. Kong, T. Takahashi, J. Org. Chem., 2005, 70, 8785-8789.
