Pd-Catalyzed Cross-Couplings: On the Importance of the Catalyst Quantity Descriptors, mol % and ppm

TY - JOUR

T1 - Pd-Catalyzed Cross-Couplings

T2 - On the Importance of the Catalyst Quantity Descriptors, mol % and ppm

AU - Horbaczewskyj, Christopher S.

AU - Fairlamb, Ian J.S.

N1 - © 2022 The Authors.

PY - 2022/8/19

Y1 - 2022/8/19

N2 - This Review examines parts per million (ppm) palladium concentrations in catalytic cross-coupling reactions and their relationship with mole percentage (mol %). Most studies in catalytic cross-coupling chemistry have historically focused on the concentration ratio between (pre)catalyst and the limiting reagent (substrate), expressed as mol %. Several recent papers have outlined the use of "ppm level"palladium as an alternative means of describing catalytic cross-coupling reaction systems. This led us to delve deeper into the literature to assess whether "ppm level"palladium is a practically useful descriptor of catalyst quantities in palladium-catalyzed cross-coupling reactions. Indeed, we conjectured that many reactions could, unknowingly, have employed low "ppm levels"of palladium (pre)catalyst, and generally, what would the spread of ppm palladium look like across a selection of studies reported across the vast array of the cross-coupling chemistry literature. In a few selected examples, we have examined other metal catalyst systems for comparison with palladium.

AB - This Review examines parts per million (ppm) palladium concentrations in catalytic cross-coupling reactions and their relationship with mole percentage (mol %). Most studies in catalytic cross-coupling chemistry have historically focused on the concentration ratio between (pre)catalyst and the limiting reagent (substrate), expressed as mol %. Several recent papers have outlined the use of "ppm level"palladium as an alternative means of describing catalytic cross-coupling reaction systems. This led us to delve deeper into the literature to assess whether "ppm level"palladium is a practically useful descriptor of catalyst quantities in palladium-catalyzed cross-coupling reactions. Indeed, we conjectured that many reactions could, unknowingly, have employed low "ppm levels"of palladium (pre)catalyst, and generally, what would the spread of ppm palladium look like across a selection of studies reported across the vast array of the cross-coupling chemistry literature. In a few selected examples, we have examined other metal catalyst systems for comparison with palladium.

KW - Buchwald-Hartwig amination cross-coupling

KW - catalysis

KW - cross-coupling

KW - cyanation

KW - direct arylation

KW - Heck

KW - Kumada

KW - Negishi

KW - palladium

KW - ppm palladium

KW - quantification

KW - Sonogashira

KW - Stille

KW - Suzuki-Miyaura

KW - synthesis

UR - http://www.scopus.com/inward/record.url?scp=85135249459&partnerID=8YFLogxK

U2 - 10.1021/acs.oprd.2c00051

DO - 10.1021/acs.oprd.2c00051

M3 - Article

AN - SCOPUS:85135249459

SN - 1083-6160

VL - 26

SP - 2240

EP - 2269

JO - Organic Process Research and Development

JF - Organic Process Research and Development

IS - 8

ER -