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Carbenes are pivotal reactive intermediates for accessing a wide range of complex molecules, which are frequently used in chemical synthesis and medicinal advancement. We have developed a convenient approach to fluorenes from α‐biaryldiazoacetates via low‐energy blue light‐induced photochemical generation of a carbene intermediate, where the reaction took place at room temperature without any catalysts, bases, or oxidants in acetonitrile. The present catalyst‐free and operationally simple approach enables highly efficient annulation of α‐biaryldiazoacetates under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract: A unified protocol for the construction of 6H‐benzofuro[2,3‐b]indoles and 5,6‐dihydroindolo[2,3‐b]indoles via UV light‐mediated diradical cyclization was developed and preliminary efforts were also made to functionalize at C10b position of 6H‐benzofuro[2,3‐b]indoles. This mild and facile strategy may have great potential in the syntheses of natural products and functional materials. [ABSTRACT FROM AUTHOR]

Abstract: (−)‐Daphnilongeranin B and (−)‐daphenylline are two hexacyclic Daphniphyllum alkaloids, each containing a complex cagelike backbone. Described herein are the first asymmetric total synthesis of (−)‐daphnilongeranin B and a bioinspired synthesis of (−)‐daphenylline with an unusual E ring embedded in a cagelike framework. The key features include an intermolecular [3+2] cycloaddition, a late‐stage aldol cyclization to install the F ring of daphnilongeranin B, and a bioinspired cationic rearrangement leading to the tetrasubstituted benzene ring of daphenylline. [ABSTRACT FROM AUTHOR]

Described herein is the first asymmetric total synthesis of (+)-harringtonolide, a natural diterpenoid with an unusual tropone imbedded in a cagelike framework. The key transformations include an intramolecular Diels-Alder reaction and a rhodium-complex-catalyzed intramolecular [3+2] cycloaddition to install the tetracyclic core as well as a highly efficient tropone formation. [ABSTRACT FROM AUTHOR]

A practical and green approach to pyrrolo- and indolo[1,2- a]quinoxalines has been developed based upon an oxidative reaction of 1-(2-aminophenyl)pyrroles or 2-(3-methyl-1 H-1-indolyl)aniline with benzylamines in the presence of O2 as the environmentally friendly oxidant and iodine as an economical and effective catalyst. [ABSTRACT FROM AUTHOR]

We have developed an environmentally benign and practical protocol for the synthesis of pyrrolo[1,2- a ]quinoxalines, which represent ubiquitous structural units common to a number of biologically active compounds. This synthetic system features simple operation and using clean oxidant, as well as mild reaction conditions. Both aromatic and aliphatic aldehydes can be used for the reaction and the products were obtained in good to excellent yields. [ABSTRACT FROM AUTHOR]

The first enantioselective total synthesis of (−)-salprzelactone, a seco-norabietane diterpenoid has been accomplished in only three steps. Key transformations of the synthesis include an intermolecular aldol reaction and lactonization. [ABSTRACT FROM AUTHOR]