The efficient and stereoselective synthesis of, or precursors to, multi-substituted alkenes has attracted substantial interest due to their existence in various industrially and biologically important compounds. One of the most atom economical routes to such alkenes is the transition metal catalyzed hetero element–element0 p-insertion into alkynes. This article provides a thorough up-to-date re...

A practical method for the multigram scale selective cis-dihydroxylation of electron deficient alkenes such as diethyl fumarate and N-alkyl and N-aryl-maleimides using H(2)O(2) is described. High turnovers (>1000) can be achieved with this efficient manganese based catalyst system, prepared in situ from a manganese salt, pyridine-2-carboxylic acid, a ketone and a base, under ambient conditions....

The photochemical C-C bond cleavage of bicyclic aziridines 7 and subsequent [3 + 2] cycloaddition with electron-deficient alkenes and alkynes afforded the novel head-to-head adducts selectively and efficiently. The adducts contain the naturally occurring 8-azabicyclo[3.2.1]octane skeleton (e.g. tropane alkaloids). The aziridine 8 fused with a 6-membered ring also afforded the cycloadducts but i...

Oxime-directed catalytic asymmetric hydroboration is diverted to catalytic asymmetric hydrogenation (CAH) upon the addition of a proton source, such as MeOH, or by running the reaction under a hydrogen atmosphere. A borane (e.g., pinacolborane) is required to promote CAH. Tri- and tetrasubstituted alkenes, including the challenging all-alkyl tetrasubstituted alkenes, undergo CAH with enantiomer...

A comparative study of the exocrine chemistry of Messor bouvieri, M. barbarus, M. lusitanicus, M. marocanus, M. arenarius, M. ebeninus, M. rugosus, M. angularis, and M. cephalotes has been carried out. Anabasine and related nicotinoids were detected in all these species except for M. barbarus, M. lusitanicus, and M. rugosus. The alkenes from the Dufour’s glands of these ants were shown to be 1-...

An efficient diastereoselective rhodium catalyzed synthesis of indolines possessing two contiguous tetrasubstituted carbon centers has been achieved with good to excellent yields using ortho-vinylanilines and iminocarbenes derived from N-sulfonyl-1,2,3-triazoles. The reaction affords excellent cisdiastereoselectivity through the initial formation of a N-ylide followed by intramolecular trapping...

The dihalogenation of alkenes is one the classic reactions in organic chemistry and a prime example an electrophilic addition reaction. often observed anti-selectivity this reaction can be explained by formation haliranium-ion intermediate. Although dihalogenations have been studied for more than century, development reagent-controlled, enantioselective has proved to very difficult. Only recent...

Key words ozonolysis - photoexcitation alkenes selectivity nitroarenes