Science - USA (2022-02-04)

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SCIENCE science.org

By Melanie Sanford

R

obert Howard (Bob) Grubbs died on

19 December 2021. He was 79. Best

known for developing catalysts that

revolutionized the way organic and

polymer chemists put molecules to-

gether, Bob was awarded the 2005

Nobel Prize in Chemistry for this work, along

with Yves Chauvin and Richard Schrock.

Grubbs was a rare example of a brilliant sci-

entist who was also a true mensch. His most

enduring legacy will be the generous friend-

ship, support, and encouragement that he

gave to colleagues, trainees, and others over

the course of his distinguished career.

Born on 27 February 1942 in rural

Kentucky, Grubbs was fascinated throughout

his youth by tinkering, building, and trying

to understand how things work. Grubbs ini-

tially planned to pursue agricultural chemis-

try, but after an early research experience, he

changed his focus to organic chemistry. After

completing his BS (1963) and MS (1965) de-

grees at the University of Florida, he earned

a PhD in 1968 at Columbia University study-

ing with chemist Ronald Breslow and com-

pleted a National Institutes of Health post-

doctoral fellowship at Stanford University

working with chemist James Collman. This

training instilled a tremendous foundation

in organic and inorganic reaction mecha-

nisms and spurred his lifelong interest in

organometallic chemistry. Grubbs started

his independent career at Michigan State

University in 1969. After 9 years, he moved

to the California Institute of Technology

(Caltech), where he maintained an active re-

search group until his death.

Grubbs spent nearly his entire career

studying a chemical reaction known as olefin

metathesis. This reaction involves the break-

ing and forming of carbon-carbon double

bonds (C=C), which are some of the strongest

bonds present in organic molecules. Olefin

metathesis was discovered in the 1950s, but

the original catalysts were poorly defined,

and their mechanisms were not well under-

stood. In his early work, Grubbs focused on

addressing these challenges by pursuing dis-

crete catalysts for this transformation and

interrogating the mechanism of the key C=C

bond cleavage and formation step.

His work in the early 1980s studying a ti-

tanium catalyst known as the Tebbe reagent

was critical in shaping his research trajectory.

It led him to recognize the power of well-

defined catalysts for achieving controlled and

predictable reactivity. However, the instabil-

ity of this titanium catalyst toward common

functional groups (Lewis bases, air, and wa-

ter) inspired his pursuit of more practical

and functional group tolerant catalysts. This

laid the groundwork for his invention of the

series of ruthenium catalysts that bear his

name. These ruthenium carbene complexes

are remarkable because they can be handled

on the benchtop and are highly selective for

C=C bonds over more Lewis basic groups.

Grubbs was the central force both in de-

veloping the fundamental science behind

ruthenium olefin metathesis catalysts and

in pioneering their translation to com-

mercial applications. In 1998, he founded

the company Materia, which scaled up the

synthesis of these catalysts and made them

widely available to the academic and indus-

trial chemistry communities. Since then,

the Grubbs catalysts have been used for the

construction of hepatitis C drugs and in the

development of biorefineries that convert

plant oils into higher-value chemicals. They

are also widely used for commercial produc-

tion of polydicyclopentadiene, a moldable

high-performance material with exceptional

impact and corrosion resistance.

Grubbs delighted not only in field-

changing scientific discoveries but also in

the more mundane aspects of academic

research. Whereas most faculty covet new

laboratory equipment, during my time in his

research group from 1997 to 2001, Grubbs

was proudest of his decades-old gloveboxes

and gel permeation chromatographs. He

regularly came through the lab to marvel

at the spectacular red, orange, purple, and

green colors of newly synthesized ruthenium

complexes. He was passionate about demon-

strations for his introductory organic chem-

istry course and loved to practice exploding

hydrogen balloons (trying to get the biggest

bang) and making polymers (trying to get

the most dramatic polymerization).

A man of wide-ranging interests outside of

the lab, Grubbs took frequent rock climbing

excursions to Joshua Tree National Park and

eagerly anticipated annual group camping

trips in northern California. He was a pas-

sionate basketball player and fan. He could

frequently be found on the sidelines of games

at Caltech, at Yale (where his daughter, Katy,

starred), and at the Staples Center, where he

was famously photographed sitting courtside

a few seats away from the late Kobe Bryant.

His love of sports endeared him to his col-

leagues and also their children; indeed, my

14-year-old son has wonderful memories of

a pickup basketball game that they played.

Beyond his scientific accomplishments,

Grubbs’s legacy is the people that he trained,

mentored, and encouraged. He advised more

than 300 graduate students and postdoctoral

fellows, who have gone on to careers in aca-

demia, industry, law, and beyond. Grubbs was

a fabulous mentor, offering trainees a balance

of scientific vision and intellectual freedom

that allowed us to discover and explore sci-

entific directions that matched our passions.

He encouraged his students to work hard

and play hard, and he was a bemused spec-

tator (and sometimes participant) in raucous

St. Patrick’s Day parties, Kit Kat tasting con-

tests, and foosball competitions.

Grubbs was exceedingly generous in ac-

cepting seminar invitations, squeezing his

six-foot-six frame into economy airplane

seats to travel around the world. As such,

thousands of scientists had the opportunity

to interact with him throughout his career.

Those visits were truly memorable for par-

ticipants. Grubbs filled his talks with folksy

words of wisdom, delivered in his character-

istic mumble. After his talks, he was just as

eager to interact with junior scientists as he

was with established professors. Hundreds

of these interactions have been shared over

the past month in an outpouring of photos

and memories on social media. Overall, Bob

Grubbs will be remembered as a brilliant

chemist who had an outsized impact on the

people around him through his love of sci-

ence, love of life, and generosity of spirit. j

10.1126/science.abo0193

RETROSPECTIVE

Robert H. Grubbs (1942–2021)

Brilliant organic chemist and inspiring mentor

Department of Chemistry, University of Michigan, Ann

Arbor, MI, USA. Email: [email protected]

4 FEBRUARY 2022 • VOL 375 ISSUE 6580 499