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Asymmetric hydrogenation of unfunctionalized trisubstituted and tetrasubstituted olefins

IP.com Disclosure Number: IPCOM000128043D
Original Publication Date: 1998-Dec-31
Included in the Prior Art Database: 2005-Sep-14
Document File: 3 page(s) / 15K

Publishing Venue

Software Patent Institute

Related People

Troutman, Malisa V: AUTHOR [+3]

Related Documents

http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-243: URL

Abstract

A highly reactive chiral catalyst for the asymmetric hydrogenation of aryl trisubstituted olefins was generated by combining the complex (EBTHI)MMe2 (EBTF11 ethylenebistetrahydroindenyl, M = Ti, Zr) with [PhMe2NH]+[(BC6F5)4]- under a hydrogen atmosphere. A number of unfunctionaiized trisubstituted olefins could be hydrogenated rapidly at room temperature under 80 psig H2 with a wide range of ee's (7 - 97%). Reduction of some substrates under a deuterium atmosphere revealed that olefins which gave low ee's were being isomerized to 1, 1disubstituted olefins prior to reduction. In some cases, additional deuterium was introduced at nonolefinic carbon atoms, indicating that the metal complexes also catalyze directed C-H activation. The zirconium-based catalyst was also applied to the first highly enantioselective hydrogenations of unfunctionalized tetrasubstituted olefins. Hydrogenations of 1,2-dimethyi-3,4-dillydronaphthalene proceeded with high enantioselectivity, but were accompanied by side reactions, At 80 - 2000 psig H2, hydrogenations of a number of fully substituted unfunctionalized indenes proceeded cleanly to give mostly cis products with ee's of 78 - 99%; rates and enantioselectivities increased with increasing pressure. Again, deuteration experiments showed that isomerization processes may occur under the reaction conditions. Thesis Supervisor; Professor Stephen L, Buchwald Title; Camille Dreyfus Professor of Chemistry

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ASYMMETRIC HYDROGENATION OF UNFUNCTIONALIZED TRISUBSTITUTED AND TETRASUBSTITUTED OLEFINS

by

Malisa V. Troutman
B.S. Chemistry, Duke University, 1992 M. Phil. Organic Chemistry, Churchill College, Cambridge University, 1993
Submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in ORGANIC CHEMISTRY

at the Massachusetts Institute of Technology

September 1998
SIGNATURE OF author: [[signature omitted]]

Department of Chemistry

July 15, 1995
CERTIFIED BY: [[SIGNATURE OMITTED]]

Stephen L. Buchwald Thesis Supervisor
ACCEPTED BY: [[SIGNATURE OMITTED]]

Dietmar Seyferth Chairman, Departmental Committee on Graduate Studies

ARCHIVES MASSACHUSETTS INSTITUTE OF TECHNOLOGY LIBRARIES SEP 30 1998

Massachusetts Institute of Technology Page 1 Dec 31, 1998

Page 2 of 3

Asymmetric hydrogenation of unfunctionalized trisubstituted and tetrasubstituted olefins

This doctoral thesis has been examined by a committee of the Department of Chemistry as follows:

Professor Timothy M. Swager

Professor Stephen L. Buchwald

Professor Gregory C, Fu

ASYMMETRIC HYDROGENATION OF UNFUNCTIONALIZED TRISUBSTITUTED AND TETRASUBSTITUTED OLEFINS

by

Malisa V. Troutman

Submitted to the Department of Chemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology

Abstract

A highly reactive chiral catalyst for the asymmetric hydrogenation of aryl trisubstituted olefins was generated by combining the complex (EBTHI)MMe2 (EBTF11

ethylenebistetrahydroindenyl, M = Ti, Zr) with [PhMe2NH]+[(BC6F5)4]- under a hydrogen atmosphere. A number of unfunctionaiized trisubstituted olefins could be hydrogenated rapidly at room temperature under 80 psig H2 with a wide range of ee's (7 - 97%). Reduction of some substrates under a deuterium atmosphere revealed that olefins which gave low ee's were being isomerized to 1, 1disubstituted olefins prior to reduction. In some cases, additional deuterium was introduced at nonolefinic carbon atoms, indicating that the metal complexes also catalyze directed C-H activation.

The zirconium-based catalyst was also applied to the first highly enantioselective hydrogenations of unfunctionalized tetrasubstituted olefins. Hydrogenations of 1,2-dimethyi-3,4- dillydronaphthalene proceeded with h...