Highly Regio- and Stereoselective Cocyclotrimerization and Linear Cotrimerization of α,β-Unsaturated Carbonyl Compounds with Alkynes Catalyzed by Nickel Complexes
作者:Thota Sambaiah、Lih-Ping Li、Daw-Jen Huang、Cheng-Hong Lin、Dinesh Kumar Rayabarapu、Chien-Hong Cheng
DOI:10.1021/jo9900580
日期:1999.5.1
degrees C affords the corresponding conjugated trienes 17a-c in 82-92% yields. The MS data of 17firmly support an adduct of two molecules of alkyne and a molecule of acrylate. Similarly, the reaction of 15a with octa-1,7-diyne in the presence of Ni(PPh(3))(2)I(2), ZnI(2), and zinc gives triene derivative 21 in 68% yield. NOE and X-ray results indicate that in these trienes the substituents from each alkyne
环烯酮2-环己烯-1-酮(1a),4,4-二甲基-2-环己烯-1-酮(1b),2-环戊烯-1-酮(1c)和2-环庚烯-1-酮( 1d)与Ni(PPh(3))(2)I(2),ZnI(2)和Zn粉在62°C下在THF中与octa-1,7-diyne(2)反应,得到[ [2 + 2 + 2]环加成-脱氢产物3a-d的产率为32-80%。对α,β-不饱和内酯5a(5,6-二氢-2H-吡喃-2-酮)进行[2 + 2 + 2]环加成反应,得到2相应的环己二烯产物6(29%)和脱氢产物7( 39%)。在相似的反应条件下,3-丁烯-2-酮与2和各种取代的庚-1,6-二炔9a-c反应,以68-80%的产率得到[2 + 2 + 2]环加成-脱氢产物11a-d 。二苯乙炔也可与1a-d,5a反应,和2(5H)-呋喃酮(5b),得到相应的[2 + 2 + 2]共环三聚产物13a-d和14a-b。在反应和后处理条件