New Efficient Multicomponent Reactions with C−C Coupling for Combinatorial Application in Liquid and on Solid Phase

Abstract

Up to nine C-C bonds are formed selectively from up to seven components starting from an alkene, a haloarene, and a dienophile [Eq. (1)]. A comparison of liquid- and solid-phase reactions reveals a surprising superiority of the solid-phase reaction.

Cyclopropyl Building Blocks in Organic Synthesis. Part 77. A New Highly Efficient Three‐Component Domino Heck—Diels—Alder Reaction with Bicyclopropylidene: Rapid Access to Spiro[2,5]oct‐4‐ene Derivatives.

“…A: Pd(OAc) 2 , PPh 3 , K 2 CO 3 , Et 4 NCl, MeCN, 80 8C, 48 h. E CO 2 Me. [26] Even the crude product showed only a single set of signals in the 13 C NMR spectrum. [24] With the easily accessible [25] methyl bicyclopropylidenecarboxylate (35 a), surprisingly, only two diastereomeric products anti,(Z)-36 a and anti,(E)-36 a (36 %, 5:4 according to GC) stemming from the opening of the unsubstituted cyclopropane ring were isolated, none of the other isomers was detected by NMR spectroscopy in the crude product.…”

Microwave‐promoted Beller Synthesis of N‐Substituted 2,3,3a,4,7,7a‐Hexahydroisoindole‐1,3‐diones

“…2, 178.1, 170.2, 135.0, 133.1, 132.6, 130.4, 129.3, 127.8, 126.8, 124.7, 45.6, 42.8, 39.1, 24.6, 23.6;IR (KBr) ν: 3295, 1707, 1657, 1379, 1184 175.4,170.2,134.8,133.5,132.6,132.2,130.3,129.2,126.9,124.8,46.1,43.9,42.5,36.7,30.7,30.4,23.6,22.7,14.2;IR (KBr) (d,J＝8.8 Hz,2H), 6.98 (d,J＝ 8.8 Hz,2H), 6.05-6.01 (m, 1H), 5.95-5.93 (m, 1H), 5.03-5.01 (m, 1H), 3.82 (s, 3H), 3.50-3.47 (m, 1H), 3.40-3.37 (m, 1H), 2.85 (dd, J＝7.2, 15.6Hz, 1H), 2.40-2.36 (m, 1H); 13 C NMR δ: 179. 2,178.8,166.9,159.9,133.9,133.2,132.0,128.8,127.8,127.7,127.3,124.1,114.8,55.7,45.9,42.8,38.9,24.6;IR (KBr) H 5.36, N 7.44; found C 70.05, H 5.37, N 7.41. 4-Acetylamino-2-(4-methoxyphenyl)-cis-2,3,3a,4, 7,7a-hexahydroisoindole-1,3-dione (4g): White solid, m.p. 155-156 ℃; 1 H NMR δ: 7.30 (d,J＝8.5 Hz,1H),…”

“…This methodology can bring molecular complexity and diversity to be created by the facile formation of several new covalent bonds in a one-pot transformation and is particularly well adapted to combinatorial synthesis. 2 Recently, Beller and coworkers 3 developed an efficient methodology for the preparation of a large variety of cyclohexene, cyclohexadiene and benzene derivatives via MCR of amides, aldehydes and dienophiles.…”

Triazene: vielseitige Verbindungen für die organische Synthese

“…[89] Zwar werden normalerweise Halogenarene oder Aryltriflate verwendet, doch kˆnnen auch als Triazene gesch¸tzte Diazoniumionen eingesetzt werden. [90] Auch mit festphasengebundenen Triazenen wurden Heck-Reaktionen durchge-f¸hrt. HBF 4 und katalytischen Mengen an Pd(OAc) 2 in siedendem Methanol durch.…”