290333-90-3Relevant articles and documents
The AZARYPHOS family of ligands for ambifunctional catalysis: Syntheses and use in ruthenium-catalyzed anti-markovnikov hydration of terminal alkynes
Hintermann, Lukas,Dang, Tuan Thanh,Labonne, Aurelie.,Kribber, Thomas,Xiao, Li,Naumov, Pance
supporting information; experimental part, p. 7167 - 7179 (2010/02/28)
The family of AZARYPHOS (aza-aryl-phosphane) phosphane ligands, containing a phosphine unit and sterically shielded nitrogen lone pairs in the ligand periphery, is introduced as a tool for developing ambifunctional catalysis by the metal center and nitrogen lone pairs in the ligand sphere. General synthetic strategies have been developed to synthesize over 25 examples of structurally diverse (6-aryl-2pyridyl)phosphanes (ARPYPHOS), (6alkyl-2-pyridyl)phosphanes (ALPY-PHOS), 4,6-disubsituted l,3-diazin-2ylphosphanes or l,3,5-triazin-2- ylphosphanes, quinazolinylphosphanes, quinolinylphosphanes, and others. The scalable syntheses proceed in a few steps. The incorporation of AZARYPHOS ligands (L) into complexes [RuCp(L)2(MeCN)][PF6] (Cp = cyclopentadieny1)gives catalysts for the anti-Markovnikov hydration of terminal alkynes of the highest known activities. Electronic and steric ligand effects modulate the reaction kinetics over a range of two orders of magnitude. These results highlight the importance of using structurally diverse ligand families in the process of developing cooperative ambifunctional catalysis by a metal and its ligand.
A general bifunctional catalyst for the anti-Markovnikov hydration of terminal alkynes to aldehydes gives enzyme-like rate and selectivity enhancements
Grotjahn, Douglas B.,Lev, Daniel A.
, p. 12232 - 12233 (2007/10/03)
A new, bifunctional catalyst for anti-Markovnikov hydration of terminal alkynes to aldehydes (6) allows practical room-temperature hydration of alkyl-substituted alkynes. Other outstanding features include near-quantitative aldehyde yields from both alkyl- and aryl-substituted alkynes and wide functional group tolerance. The uncatalyzed rate of alkyne hydration is measured for the first time, showing the enzyme-like rate and selectivity enhancements of aldehyde formation by 6. For aldehyde formation, an uncatalyzed rate -10 mol h-1 means a half-life >600 000, years. The catalyzed rate is up to 23.8 mol (mol 6)-1 h-1 and 10 000:1 ratio in favor of aldehyde. Changes in rate and selectivity induced by 6 are thus >2.4 × 1011 and 300 000, respectively. Copyright
