分别从四环二聚体1的桥裂反应和阴离子交换反应中可以轻松制备出两种新的含氯/碘阴离子2-3的三苯基膦-环钯的二茂铁基吡嗪络合物。它们通过元素分析,IR和1 H NMR表征。此外,通过单晶X射线分析确定了这两个配合物的结构,并在它们的晶体结构中发现了C–H···N氢键和π–π相互作用。这些配合物在大气条件下在末端炔烃与芳基硼酸的偶联中显示出良好的活性。该方法为相应的芳基炔烃提供了良好或优异的收率。
Dual gold/photoredox-catalyzed C(sp)–H arylation of terminal alkynes with diazonium salts
作者:Adrian Tlahuext-Aca、Matthew N. Hopkinson、Basudev Sahoo、Frank Glorius
DOI:10.1039/c5sc02583d
日期:——
The arylation of alkyl and aromatic terminal alkynes by a dual gold/photoredoxcatalytic system is described. Using aryldiazonium salts as readily available aryl sources, a range of diversely-functionalized arylalkynes could be synthesized under mild, base-free reaction conditions using visible light from simple household sources or even sunlight. This process, which exhibits a broad scope and functional
描述了金/光氧化还原双催化系统对烷基和芳族末端炔烃的芳基化。使用芳基重氮盐作为容易获得的芳基源,可以使用来自简单家庭来源的可见光甚至阳光,在温和、无碱的反应条件下合成一系列不同官能化的芳基炔。该过程表现出广泛的范围和官能团耐受性,将双金/光氧化还原催化的转化范围扩大到涉及 C-H 键功能化的转化范围,并证明了该概念在以下条件下获得 Au I / Au III氧化还原化学的潜力:温和的氧化还原中性条件。
Cp∗Li as a base: application to palladium-catalyzed cross-coupling reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminal acetylenes
作者:Minoru Uemura、Hideki Yorimitsu、Koichiro Oshima
DOI:10.1016/j.tet.2007.11.095
日期:2008.2
The reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminalacetylenes in the presence of a catalytic amount of Pd(OAc)2 provided the alkynylated products in good yields by using Cp∗Li (Cp∗=1,2,3,4,5-pentamethylcyclopentadienyl) as a base.
Alkynylzinc reagents were found to undergo coupling with aryl and alkenyl iodides to give arylalkynes and alkenylalkynes with no aid of transition metals. The coupling reaction proceeds through a single...
An iron‐catalyzed diboration reaction of alkynes with bis(pinacolato)diboron (B2pin2) and external borating agents (MeOB(OR)2) affords diverse symmetrical or unsymmetrical cis‐1,2‐diborylalkenes. The simple protocol for the diboration reaction can be extended to the iron‐catalyzed carboboration of alkynes with primary and, unprecedentedly, secondary alkyl halides, affording various tetrasubstituted
Acetylene compound, liquid crystal composition and liquid crystal element
申请人:Mitsui Chemicals, Inc.
公开号:US06217793B1
公开(公告)日:2001-04-17
Provided are novel acetylene compounds which are useful as a component for a liquid crystal composition used for a liquid crystal element, a liquid crystal composition containing said compounds and a liquid crystal element using said liquid crystal composition. The acetylene compound is represented by Formula (1):
n-CmH2m+1—C≡C—A—Z1—B—Y1—R1 (1)
wherein m represents an integer of 2 to 24; R1 represents a linear or branched alkyl group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or a linear or branched alkenyloxyalkyl group each of which may be substituted with a halogen atom; R1 may have an asymmetric carbon atom, and the asymmetric carbon atom may be optically active; A and B represents a cyclic group such as a phenylene group, a biphenylene group, a naphthylene group and the like each of which may be substituted with a halogen atom.