Question: Yves Chauvin was a French chemist who won a Nobel Prize while working with which American co-founder of Materia?
Context: Yves Chauvin (] ; October 10, 1930 – January 27, 2015) was a French chemist and Nobel Prize laureate.  He was honorary research director at the "Institut français du pétrole" and a member of the French Academy of Science.  He was known for his work for deciphering the process of metathesis for which he was awarded the 2005 Nobel Prize in Chemistry along with Robert H. Grubbs and Richard R. Schrock. Robert Howard Grubbs (born February 27, 1942) is an American chemist and the Victor and Elizabeth Atkins Professor of Chemistry at the California Institute of Technology in Southern California.  He was a co-recipient of the 2005 Nobel Prize in Chemistry for his work on olefin metathesis.  He is a co-founder of Materia, a University spin-off startup to produce catalysts. Jean-Marie Lehn (born 30 September 1939) is a French chemist.  He received the Nobel Prize in Chemistry together with Donald Cram and Charles Pedersen in 1987 for his synthesis of cryptands. Lehn was an early innovator in the field of supramolecular chemistry, i.e., the chemistry of host-guest molecular assemblies created by intermolecular interactions, and continues to innovate in this field.  His group has published in excess of 900 peer-reviewed articles in chemistry literature. The Nobel Prize in Physiology or Medicine (Swedish: "Nobelpriset i fysiologi eller medicin" ), administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the fields of life sciences and medicine.  It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will.  Nobel was personally interested in experimental physiology and wanted to establish a prize for progress through scientific discoveries in laboratories.  The Nobel Prize is presented to the recipient(s) at an annual ceremony on 10 December, the anniversary of Nobel's death, along with a diploma and a certificate for the monetary award.  The front side of the medal provides the same profile of Alfred Nobel as depicted on the medals for Physics, Chemistry, and Literature; its reverse side is unique to this medal. Since 1901, the Nobel Prize in Literature (Swedish: "Nobelpriset i litteratur" ) has been awarded annually to an author from any country who has, in the words of the will of Alfred Nobel, produced "in the field of literature the most outstanding work in an ideal direction" (original Swedish: "den som inom litteraturen har producerat det mest framstående verket i en idealisk riktning").  Though individual works are sometimes cited as being particularly noteworthy, here "work" refers to an author's work as a whole.  The Swedish Academy decides who, if anyone, will receive the prize in any given year.  The academy announces the name of the chosen laureate in early October.  It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895; the others are the Nobel Prize in Chemistry, Nobel Prize in Physics, Nobel Peace Prize, and Nobel Prize in Physiology or Medicine. Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds.  Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative organic reactions.  For their elucidation of the reaction mechanism and their discovery of a variety of highly active catalysts, Yves Chauvin, Robert H. Grubbs, and Richard R. Schrock were collectively awarded the 2005 Nobel Prize in Chemistry. The Nobel Prize in Physiology or Medicine (Swedish: "Nobelpriset i fysiologi eller medicin" ) is awarded annually by the Swedish Karolinska Institute to scientists and doctors in the various fields of physiology or medicine.  It is one of the five Nobel Prizes established by the 1895 will of Alfred Nobel (who died in 1896), awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine.  As dictated by Nobel's will, the award is administered by the Nobel Foundation and awarded by a committee that consists of five members and an executive secretary elected by the Karolinska Institute.  While commonly referred to as the Nobel Prize in Medicine, Nobel specifically stated that the prize be awarded for "physiology or medicine" in his will.  Because of this, the prize can be awarded in a broader range of fields.  The first Nobel Prize in Physiology or Medicine was awarded in 1901 to Emil Adolf von Behring, of Germany.  Each recipient receives a medal, a diploma and a monetary award that has varied throughout the years.  In 1901, von Behring received 150,782 SEK, which is equal to 7,731,004 SEK in December 2008.  In 2013, the prize was awarded to James E. Rothman, Randy W. Schekman and Thomas C. Südhof; they were recognised "after discovering how cells precisely transport material".  The award is presented in Stockholm at an annual ceremony on December 10, the anniversary of Nobel's death. Ferdinand Frederick Henri Moissan (28 September 1852 – 20 February 1907) was a French chemist who won the 1906 Nobel Prize in Chemistry for his work in isolating fluorine from its compounds.  Moissan was one of the original members of the International Atomic Weights Committee. Paul Sabatier FRS (] ; 5 November 1854 – 14 August 1941) was a French chemist, born in Carcassonne.  In 1912, Sabatier was awarded the Nobel Prize in Chemistry along with Victor Grignard.  Sabatier was honoured specifically for his work improving the hydrogenation of organic species in the presence of metals. Grubbs' catalysts are a series of transition metal carbene complexes used as catalysts for olefin metathesis.  They are named after Robert H. Grubbs, the chemist who supervised their synthesis.  Several generations of the catalyst have been developed.  Grubbs' catalysts tolerate many functional groups in the alkene substrates, are air-tolerant, and are compatible with a wide range of solvents.  For these reasons, Grubbs' catalysts have become popular in synthetic organic chemistry.  Grubbs, together with Richard R. Schrock and Yves Chauvin, won the Nobel Prize in Chemistry in recognition of their contributions to the development of olefin metathesis.
Answer: Robert H. Grubbs