Activation of Mononuclear Arene Ruthenium Complexes for Catalytic Propargylation Directly with Propargyl Alcohols
作者:Emilio Bustelo、Pierre H. Dixneuf
DOI:10.1002/adsc.200600512
日期:2007.4.2
ligand. The in situ generated catalyst has been applied to catalytic transformations of alkynes and propargylic alcohols: propargylation of furans, propargyl ether synthesis from internal and terminal propargylic alcohols with propargyl, homopropargyl and allyl alcohols, selective dimerization of phenylacetylene into E-enyne, and propargyl alcohol rearrangement into α,β-unsaturated aldehydes and ketones
[(对伞花基)RuX(CO)(PR 3)] [OTf](R = Ph,Cy; X = Cl,OTf)类型的单核络合物促进呋喃与炔丙醇的直接催化炔丙基化。这些前体是通过活化炔丙醇从[(对-cymene)RuCl(OTf)(PR 3)]原位产生的,导致经由亚烯基和烯基-羟基卡宾中间体形成羰基配体。催化活性物质的产生需要短的初始热活化以诱导对-异丙基配体的去配位。在原位生成的催化剂已用于炔烃和炔丙醇的催化转化:呋喃的炔丙基化,内部和末端炔丙醇与炔丙基,高炔丙基和烯丙基醇的炔丙基醚合成,苯乙炔的选择性二聚为E-烯炔和炔丙醇重排为α ,β-不饱和醛和酮通过Meyer-Schuster重排。含有内部CC键的炔丙醇的炔丙基化表明通过Nicholas型中间体(金属稳定的炔丙基阳离子)的活化。
Highly Stereoselective Generation of Complex <i>Oxy</i>-Bicyclic Scaffolds <i>via</i> an Atom-Economic Pd(II)-Catalyzed Hydroalkynylation, Isomerization and Diels–Alder Cycloaddition Sequence
Pd(II)-catalyzed hydroalkynylation, alkyne-allene isomerization, and Diels–Alder cycloaddition is reported. The reaction employs readily available starting substrates, proceeds in a highly ordered fashion, features high regio- and stereoselectivity, and tolerates a wide range of functionality and structural motifs, thus offering an attractive strategy for producing new molecular complexity and diversity from easily
Silaborative Carbocyclizations of 1,7-Enynes. Diastereoselective Preparation of Chromane Derivatives
作者:You-Cai Xiao、Christina Moberg
DOI:10.1021/acs.orglett.5b03479
日期:2016.1.15
Palladium(0)-catalyzed carbocyclization of 1,7-enynes mediated by (chlorodimethylsilyl)pinacolborane proceeds with 1,8-addition of the silicon and boron functions to give functionalized cyclohexane derivatives with boron attached to the exocyclic olefin. A variety of chromane dervatives are accessible by this method. In contrast to the analogous reactions with 1,6-enynes, the configuration of the newly
Unexpected Domino Reaction via Pd-Catalyzed Sonogashira Coupling of Benzimidoyl Chlorides with 1,6-Enynes and Cyclization To Synthesize Quinoline Derivatives
A domino reaction via palladium-catalyzed Sonogashira coupling of benzimidoyl chlorides with 1,6-enynes and then cyclization to form quinoline derivatives has been developed. The reaction conditions and the scope of the process are examined, and a plausible mechanism is proposed. The procedure is simple, rapid, and general, and the substrates are readily available.
Palladium-Catalyzed Silastannation of Secondary Propargylic Alcohols and their Derivatives
作者:David Tanner、Thomas E. Nielsen、Sebastian Le Quement
DOI:10.1055/s-2004-822380
日期:——
A series of terminal propargylic alcohols and their derivatives were subjected to Pd-catalyzed silastannation. In all reactions, complete regio- and stereoselectivities were observed with the tributyltin moiety exclusively adding to the internal carbon of the triple bond in a cis fashion, including the first example of a diyne bis-silastannation. Silastannation reaction products could sequentially