An Improved Protocol for the Synthesis of Allylated Isonitriles
作者:Uli Kazmaier、Stefanie Ackermann
DOI:10.1055/s-2004-834829
日期:——
α-Isocyanoacetates can be used as suitable nucleophiles in palladium-catalyzed allylic alkylations giving rise to α-allylated isonitriles. Best results are obtained if Cs2CO3 is used as a base to deprotonate the isonitrile, and with dppe as a ligand on palladium, which supresses decomposition of the active palladium complex.
Highly regioselective [3,3] rearrangement of aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin complex, Cr(TPP)Cl
作者:Toshikatsu Takanami、Mikiko Hayashi、Kazuhiro Iso、Hirose Nakamoto、Kohji Suda
DOI:10.1016/j.tet.2006.07.051
日期:2006.10
Claisen rearrangement of simple aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin, Cr(TPP)Cl, is described. The porphyrin-based Lewis acid catalyst can effectively accelerate the rearrangement via a concerted [3,3] pathway with a minimal degree of bond ionization of the substrates, providing the corresponding Claisen products in moderate to high yields and almost perfect regioselectivity at low
Metalloporphyrin-Catalyzed Diastereoselective Epoxidation of Allyl-Substituted Alkenes
作者:Wing-Kei Chan、Man-Kin Wong、Chi-Ming Che
DOI:10.1021/jo047733c
日期:2005.5.1
developed an efficient method for erythro-selective epoxidation of acyclic allyl-substituted alkenes, including allylic alcohols, amines, and esters. Up to 9:1 erythro selectivities for terminal allyllic alkenes could be achieved, which are significantly higher than that achieved using m-CPBA as an oxidant. In addition, the synthetic utilities of this epoxidation method were highlighted in stereoselective synthesis
通过使用[Mn(2,6-Cl 2 TPP)Cl](1)作为催化剂,Oxone / H 2 O 2作为氧化剂,我们开发了一种有效的方法,用于无环烯丙基取代的烯烃的赤型选择性环氧化,包括烯丙醇,胺和酯。末端烯丙基烯烃可达到9:1的赤型选择性,这明显高于使用m -CPBA作为氧化剂所达到的选择性。此外,这种环氧化方法的合成效用在关键的抗HIV药物中间体的立体选择性合成和糖基的环氧化中得到了强调。
Activation and synthetic applications of thiostannanes. Protection of carboxyl groups with α-methylcinnamyl alcohol as a means of chemodifferentiation and selective activation
作者:Tsuneo Sato、Junzo Otera、Hitosi Nozaki
DOI:10.1016/s0040-4039(00)99169-x
日期:1989.1
α-Methylcinnamyl (MEC) esters are converted into parent carboxylic acids under mild conditions, various functions being tolerated including acetoxy, siloxy, MEM, and so on. Furthermore, MEC esters are transformed into other esters through CsF-promoted alkylation of intermediary organotin carboxylates.