Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation
| Main Author: | |
|---|---|
| Language: | English |
| Published: |
University of Toledo / OhioLINK
2018
|
| Subjects: | |
| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525441044040006 |
| id |
ndltd-OhioLink-oai-etd.ohiolink.edu-toledo1525441044040006 |
|---|---|
| record_format |
oai_dc |
| spelling |
ndltd-OhioLink-oai-etd.ohiolink.edu-toledo15254410440400062021-08-03T07:06:47Z Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation Basiouny, Miriam M.I. Chemistry Phosphines and phosphine oxides have been indispensable tools in different areas of chemistry including organometallics, pharmaceuticals, and agrochemicals. With the increasing need of specialized phosphines and phosphine oxides, chemists turned to catalytic hydrophosphination (the addition of an H-P bond across an unsaturated system) and hydrophosphinylation (the addition of an H-P(O) bond across an unsaturated system). A lanthanum (III) catalyst supported by a-metalated N,N-dimethylbenzylamine ligands (La(Dmba)3) was used to induce the first example of direct double hydrophosphinylation of unactivated nitriles, yielding different regioisomeric products depending on the nature of the nitrile. Primary alkyl nitriles undergo 1,1-addition to give products with a new P-C-P linkage and a primary amine. Secondary and aryl nitriles undergo 1,2-addition to yield a new P-C-N-P linkage under the same conditions. Further investigation into the catalytic cycle showed that all nitriles first undergo 1,1-addition and then undergo isomerization to the final unsymmetric product. La(Dmba)3 was also the first catalyst to induce both hydrophosphination and hydrophosphinylation of alkynes under mild conditions. This too showed interesting selectivity. In the case of hydrophosphination, the catalyst induced mono-addition with high regiospecificity, yielding only the anti-Markovnikov product. The stereoselectivity of the final products can be controlled based on the reaction conditions. Undertaking the catalysis with excess phosphine yielded the E-isomer as the major product; however, using excess alkyne, the Z-isomer was isolated as the major product. A brief investigation into the catalytic cycle suggests that a dimeric form of lanthanum phosphide active catalyst forms the Z-isomers as kinetic products that then undergo isomerization to yield the final E-isomers. In the case of hydrophosphinylation, the chemoselectivity depended on the nature of alkyne. Terminal alkynes only showed double addition products while single and double addition products were both successfully isolated in the case of internal alkynes. This reaction also showed high chemo-and regioselectivity. The lanthanum-based catalyst was shown to be very effective in inducing unusual hydrophosphination and hydrophosphinylation products with high control of selectivity. 2018-12-21 English text University of Toledo / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525441044040006 http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525441044040006 unrestricted This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Chemistry |
| spellingShingle |
Chemistry Basiouny, Miriam M.I. Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| author |
Basiouny, Miriam M.I. |
| author_facet |
Basiouny, Miriam M.I. |
| author_sort |
Basiouny, Miriam M.I. |
| title |
Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| title_short |
Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| title_full |
Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| title_fullStr |
Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| title_full_unstemmed |
Lanthanum Catalyzed Hydrophosphination and Hydrophosphinylation |
| title_sort |
lanthanum catalyzed hydrophosphination and hydrophosphinylation |
| publisher |
University of Toledo / OhioLINK |
| publishDate |
2018 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525441044040006 |
| work_keys_str_mv |
AT basiounymiriammi lanthanumcatalyzedhydrophosphinationandhydrophosphinylation |
| _version_ |
1719454100757676032 |