Asymmetric α-Pentadienylation of Aldehydes with Cyclopropylacetylenes

Rh(II)-Catalyzed Alkynylcyclopropanation of Alkenes by Decarbenation of Alkynylcycloheptatrienes

“…This grants easy access to another type of versatile synthetic intermediates, avoiding the use of synthetically challenging 7-allenyl-1,3,5-cycloheptatrienes, which have not been described so far. All these new reactions, together with previous reports on the use of alkynylcyclopropanes in the discovery of novel methodologies, − highlight the versatility and potential of these now readily accessible compounds.…”

“…Accordingly, great efforts have been made to grant access to a wide variety of three-membered rings in a straightforward manner . In particular, alkyne-substituted cyclopropanes display very diverse reactivity patterns and have been used by different research groups as starting substrates for the development of new synthetic methodologies through ring-expansion, ring-opening, or cycloaddition processes, among others . The versatility of these intermediates has been further illustrated by their application in the total synthesis of natural products .…”

Combined Power of Organo‐ and Transition Metal Catalysis in Organic Synthesis

“…Different multicatalytic approaches describing combined effect of diverse catalytic systems have been studied and presented from time to time. [19][20][21][22][23][24] Also, the combination of organocatalysis with photocatalysis is an emerging area of research. The use of chiral organocatalysis with organometallic photocatalysts allows new synthetic routes to enantioenriched molecules.…”

“…The advantages include enhanced reactivity, improved rate of the existing reactions and introduction of stereocenter in the newly formed compounds. Different multi‐catalytic approaches describing combined effect of diverse catalytic systems have been studied and presented from time to time [19–24] . Also, the combination of organocatalysis with photocatalysis is an emerging area of research.…”

Cyclopropanation of Propargyl Sulfonium Salts: Highly Diastereoselective Synthesis of Alkynylcyclopropanes

“…Alkyne-substituted cyclopropanes are prominent structural motifs in many natural products, biologically active molecules, and pharmaceuticals. − Meanwhile, the highly strained three-membered rings can also serve as versatile reactants in organic synthesis attributed to their high reactivity (Scheme c). − Over the past decades, several strategies for the preparation of alkynyl cyclopropane have been reported, such as the cyclopropanation of alkynyl carbenoids − or 1,3-enynes, − hydroalkynylation, − and some isolated examples. − However, there are few reports on the synthesis of alkynylcyclopropanes with three contiguous stereocenters. Thus, new synthetic approaches for the efficient construction of polysubstituted alkynylcyclopropanes from easily accessible materials in a highly diastereoselective manner would be instructive to make diverse molecules rapidly and easily.…”