Hydroalkoxylation rhodium

The Trost group has disclosed two methods of rhodium vinylidene-mediated hydrofunctionalization (i) intramolecular hydroalkoxylation of alkynols and... 

C-M bond addition, for C-C bond formation, 10, 403-491 iridium additions, 10, 456 nickel additions, 10, 463 niobium additions, 10, 427 osmium additions, 10, 445 palladium additions, 10, 468 rhodium additions, 10, 455 ruthenium additions, 10, 444 Sc and Y additions, 10, 405 tantalum additions, 10, 429 titanium additions, 10, 421 vanadium additions, 10, 426 zirconium additions, 10, 424 Carbon-oxygen bond formation via alkyne hydration, 10, 678 for aryl and alkenyl ethers, 10, 650 via cobalt-mediated propargylic etherification, 10, 665 Cu-mediated, with borons, 9, 219 cycloetherification, 10, 673 etherification, 10, 669, 10, 685 via hydro- and alkylative alkoxylation, 10, 683 via inter- andd intramolecular hydroalkoxylation, 10, 672 via metal vinylidenes, 10, 676 via SnI and S Z processes, 10, 684 via transition metal rc-arene complexes, 10, 685 via transition metal-mediated etherification, overview,... 

Chiral allylic phosphine oxides were synthesized by the rhodium-catalyzed asymmetric hydroalkoxylation of diphenylhosphinylallenes (Scheme 37). Using thiophenols, hydrosulfenylation reactions were carried out." ... 

DFT calculation revealed the origin of the (Z)-selectivity of the anft -Markovnikov hydroalkoxylation of terminal alkynes (122), catalysed by the rhodium(I) 8-quinolinolato carbonyl chelate (123). The reaction is likely to commence by the formation of the // -complex PhC=CH[Rh], which tautomerizes via a 1,2-hydrogen shift to generate the Rh(I) vinylidene complex PhCH=C=[Rh]. Methanol, as an oxygen nucleophile, then attacks the Ca, and via the transition state (124), which is 1.2kcalmol lower in energy than its stereoisomer, thus giving the (Z)-vinyl ether (125). An improvement in the (Z)-selectivity in the related Rh(I)-catalysed 0... 

Kawamoto T, Hirabayashi S, Guo X, Nisbimura T, Hayasbi T. Rhodium-catalyzed asymmetric hydroalkoxylation and hydrosulfenylation of diphenylphosphinylallenes. Chem. Commun. 2009 3528-3530. 

Kondo M, Kochi T, Kakiuchi F (2011) Rhodium-catalyzed anti-markovnikov intermolecular hydroalkoxylation of terminal acetylenes. J Am Chem Soc 133 32-34... 

Messerle BA, Vuong KQ (2007) Rhodium- and iridium-catalyzed double hydroalkoxylation of alkynes an efficient method for the synthesis of O, 0-acetals catalytic and mechanistic studies. Organometallics 26 3031-3040... 

---