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An effective approach to the synthesis of thieno[2,3‐g]indolizine derivatives has been developed. A wide variety of reagents such as unsaturated aldehydes, methylvinylketone, esters of acrylic acid, maleic anhydride, methyl propiolate, dimethyl and diethyl acetylenedicarboxylates in the construction of functionally diverse rarely encountered tricyclic system has been used. A high number of structurally various thieno[2,3‐g]indolizines has been obtained in domino reactions with medium and high yields, the influence of solvents on the course of transformations has been studied, and the presence of moderate cytotoxic activity for a number of compounds has been established. [ABSTRACT FROM AUTHOR]

The title compound, C19H19NO5, (I), is the product of a domino reaction between cotarnine chloride and acetyl­acetylene catalysed by copper(I) iodide. The mol­ecule of (I) comprises a fused tetra­cyclic system containing two terminal five-membered rings (pyrrole and 1,3-dioxole) and two central six-membered rings (di­hydro­pyridine and benzene). The five-membered 1,3-dioxole ring has an envelope conformation and the central six-membered di­hydro­pyridine ring adopts a twist-boat conformation. The acyl substituent is almost coplanar with the pyrrole ring, whereas the meth­oxy substituent is twisted by 27.93 (16)° relative to the benzene ring. The 2-oxopropan-1-yl substituent is roughly perpendicular to the pyrrole ring. In the crystal, mol­ecules are stacked along the a-axis direction; the stacks are linked by weak C—H···O hydrogen bonds into puckered layers lying parallel to (001). [ABSTRACT FROM AUTHOR]

An efficient synthetic approach to access (indol-3-yl)ethane-1,2-diamines with a protecting group at the indole N atom from readily available 3-(2-nitrovinyl)indoles is reported. This approach includes solvent-free conjugate addition of O-pivaloylhydroxylamines to 1-Boc-3-(2-nitrovinyl)indoles followed by mild reduction of the adducts. The obtained (indol-3-yl)ethane-1,2-diamines are convenient synthetic precursors for several classes of marine alkaloids. The first total synthesis of racemic topsentin C, a secondary metabolite from Hexadella sp., based on this approach is reported. The initially proposed structure for topsentin C has been revised. [ABSTRACT FROM AUTHOR]

Cyanomethyl-substituted tetrahydroisoquinolines and tetrahydrothieno[3,2- c ]pyridines were synthesized by multicomponent reaction of the dihydro analogues of aforesaid systems with benzyne and acetonitrile. The products obtained relate to alkaloids of isoquinoline family of 1,2,3,4-tetrahydro level. [ABSTRACT FROM AUTHOR]

The synthesis of pharmacologically relevant isoquinoline-tetrazoles and benzazocine-tetrazoles via sequential azido-Ugi and alkyne-induced ring-expansion reactions starting from cotarnine chloride are reported. A one-pot, multicomponent reaction protocol toward the ring-expanded product is also described. [ABSTRACT FROM AUTHOR]

Abstract: The interaction between 1-furyl-1,2,3,4-tetrahydroisoquinolines and unsaturated acids derivatives (acryloyl, methacryloyl, and crotonoyl chloride, maleic and citraconic anhydride) was studied. It was shown that the reaction proceeds via amide formation and subsequent intramolecular Diels–Alder reaction of the furan (IMDAF). The [4+2] cycloaddition proceeded under mild reaction conditions (25–80°C) and afforded only the exo-adduct in a high yield. With this method, a new approach to the isoindolo[1,2-a]isoquinoline system, the basic structural element of alkaloids Jamtine, Hirsutine, and Nuevamine, is proposed. [Copyright &y& Elsevier]

Abstract: 1-(2-Furyl)-3,4-dihydroisoquinolines, easily prepared from readily available phenethylamines, undergo tandem alkylation/[4+2]-cycloaddition with allyl halides. The reaction proceeds via 2-allyl-1-furyl-3,4-dihydroisoquinolinium salt formation and subsequent intramolecular exo-Diels–Alder reaction of furan with the allyl fragment (IMDAF reaction). The adducts formed include the basic structural element of the isoindolo[1,2-a]isoquinoline alkaloids jamtine and hirsutine. [ABSTRACT FROM AUTHOR]

• A novel approach to the synthesis of the previously inaccessible compounds. • The structure of the compounds ensured with single X-ray crystal analysis. • The process can be described as one-pot domino reaction. • A number of hydrogenated benzo h pyrrolo[2,1- a isoquinoline derivatives have been obtained in yields close to 90%. An effective strategy for the synthesis of benzo h pyrrolo[2,1- a isoquinoline derivatives has been developed. The process can be described as a one-pot domino reaction that consists of an initial Michael addition, intramolecular cyclization, and subsequent transformations leading to the formation of the desired products. A wide range of structurally diverse hydrogenated benzo h pyrrolo[2,1- a isoquinolines were obtained in 34–98% yield. This strategy represents an efficient catalyst-free procedure that allows the synthesis of previously inaccessible compounds. [ABSTRACT FROM AUTHOR]