Mercuric Triflate-Catalyzed Synthesis of 2-Methylfurans from 1-Alkyn-5-ones
摘要:
2-Methylfurans were prepared by an effective cyclization of 1-alkyn-5-ones in the presence of mercuric triflate as the catalyst under very mild reaction conditions with high catalytic turnover up to 100 times. Benzene, toluene, or dichloromethane was the solvent of choice.
highly efficient and practical synergisticallymetal/proton‐catalyzed Conia–ene reaction for the synthesis of bicyclo[3.n.1]alkanones has been developed. This synergisticcatalysis was successfully utilized in modifying natural compounds such as methyl dihydrojasmonate, α,β‐thujone, and 5α‐cholestan‐3‐one. Furthermore, the bridged carbonyl group of bicyclo[3.2.1]alkanones could be easily attacked by nucleophiles
Synthesis of functionalised furans and pyrroles through annulation reactions of 4-pentynones
作者:Antonio Arcadi、Elisabetta Rossi
DOI:10.1016/s0040-4020(98)00953-3
日期:1998.12
A new approach to 4-pentynones through palladium-catalysed coupling reaction of the ready available 2-propynyl ketones with aryl iodides and/or vinyl triflates is proposed. Annulation reactions of both 2-propynyl ketones and 4-pentynones gave functionalised furans using potassium tert-butoxide in DMF and functionalised pyrroles in the presence of benzylamine or ammonia, respectively in good to high
tethered with a vinyl azide group undergo a Schmidt-hydrolysis sequence to give secondary lactams bearing a ketone side chain. Secondary lactams are obtained in a regioselective manner that is not possible in a conventional Schimdt reaction. In addition to the well-documented C-2 nucleophilicity, the N nucleophilicity of vinyl azide disclosed in this work opens a new direction for reaction invention involving
Catalyst component for polymerization of alpha-olefins and process for
申请人:Mitsubishi Chemical Corporation
公开号:US06084043A1
公开(公告)日:2000-07-04
A catalyst component for the polymerization of alpha-olefins, represented by the following formula [I]: ##STR1## wherein R.sup.1 -R.sup.3 =H, a halogen, a C.sub.1-10 hydrocarbon radical, a Si-containing C.sub.1-18 hydrocarbon radical, or a halogen-containing C.sub.1-10, hydrocarbon radical (provided that R.sup.1 and R.sup.2 cannot be hydrogen at the same time); n=2 to 7; Q=a C.sub.1-20 hydrocarbon radical, a silylene or oligosilylene group having or not having a C.sub.1-20 hydrocarbon radical, a germylene group having or not having a C.sub.1-20 hydrocarbon radical; X and Y=H, a halogen, a C.sub.1-20 hydrocarbon radical, or an O- or N-containing C.sub.1-20 hydrocarbon radical; and M=a transition metal selected from the groups IVB-VIB; a catalyst for the polymerization of alpha-olefins, comprising the catalyst component; and a process for producing alpha-olefin polymers, where use is made of the catalyst. Use of the catalyst will produce alpha-olefin polymers having a high melting point and a high molecular weight in a high yield.
一种催化剂组分,用于α-烯烃的聚合,其由以下式[I]表示:##STR1## 其中R.sup.1-R.sup.3 = H,卤素,C.sub.1-10烃基,含硅C.sub.1-18烃基,或含卤素的C.sub.1-10烃基(前提是R.sup.1和R.sup.2不能同时为氢); n = 2至7; Q = C.sub.1-20烃基,具有或不具有C.sub.1-20烃基的硅亚烷或寡硅亚烷基,具有或不具有C.sub.1-20烃基的锗亚烷基; X和Y = H,卤素,C.sub.1-20烃基,或含O或N的C.sub.1-20烃基; M = 从IVB-VIB族选择的过渡金属; 包括催化剂组分的α-烯烃聚合催化剂;以及使用催化剂生产α-烯烃聚合物的过程。使用该催化剂将产生高熔点和高分子量的α-烯烃聚合物,并且产量高。