Alkyne hydrative

The rhodium-catalyzed intermolecular hydrative dimerization of 1-alkynes leads to a,/3-unsaturated ketones (Equation (190)).154... 

Using established principles of late-transition metal catalysis, several research groups have engineered multi-component coupling reactions from the basis set of known Group 9 metal vinylidene-mediated reactions. In 2004, Jun and coworkers described a new method for the synthesis of enones via rhodium vinylidene-mediated hydrative dimerization of alkynes (Table 9.12) [24]. 

Scheme 9.11 Proposed mechanism for hydrative dimerization of terminal alkynes.

Chatani and coworkers published an efficient method for the Rh(I)-catalyzed anti-Markovnikov hydroamination of terminal alkynes using either primary or secondary amines [58]. This reactivity had been observed earlier in the course of their studies on hydrative alkyne dimerization (Equation 9.8). 

While enynes are common products in the reaction of 1-alkynes under Wilkinson s catalyst, hydrative dimerization products of 1-alkyne with H2O are obtained in the presence of an additional cocatalyst, 2-amino-3-picoline. For instance, when the reaction of terminal alkynes and FI2O is carried out using the catalytic system of RhCl(PPh3)3, 2-amino-3-picoline, and benzoic acid in THF, a mixture of branched a,/3-enone and linear enone can be obtained in a 4 1 ratio (eq 81). ... 

Copper-catalyzed hydrative amide synthesis with terminal alkyne, sulfonyl azide, and water, (b) M. P. Cassidy, J. Raushel, V. V. Fokin, Angew. Chem. Int. Ed. 2006,4, 3154-3157. Practical synthesis of amides from in situ generated copper(I) acetyhdes and sulfonyl azides, (c) S. H. Cho, S. Chang, Angew. Chem. Int. Ed. 2007, 46, 1897-1900. Rate-accelerated nonconventional amide synthesis in water a practical catalytic aldol-surrogate reaction. 

Hydr< ormylation of Unfunctionalized Monoolefins, Polyolefins, and Alkynes 295... 

CCS can be introduced into injectable materials by separately modifying soluble polymer chains with a pair of molecules that have specific affinity to each other. When these modified polymeric chains are injected simultaneously to the cross-linking site, they undergo rapid cross-linking to give rise to a covalent cross-linked network. The most commonly used pairs of molecules with specific affinities towards each other are iV-hydr-oxysuccinimide (-NHS) to amine (-NH2), 1,4-addition of a doubly stabilized carbon nucleophile to an a,p-unsaturated carbonyl compound (Michael-type addition reaction), and alkyne to azide (click chemistry). In these types of reactions, the rate, stability, and kinetics of network formation are solely dependent upon the strength of the affinity of one molecule to its counterpart. 

Das et al. reported a synthetic method of chrysene framework 46 by hydrative dimerization of o-alkynylacetophenone 11 with PtCl2 catalyst in a CO atmosphere (Scheme 15.17). The tandem catalysis comprises an initial selective hydration of the alkyne, followed by chemoselective dimerization of diketone intermediates [29]. Kuznetsov and Verin reported the synthesis of chrysene framework by dimerization of benzopyrylium salts [30]. 

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