Catalytic Enantioselective Hydrogenation of N-Alkoxycarbonyl Hydrazones: A Practical Synthesis of Chiral Hydrazines
摘要:
An enantioselective hydrogenation of hydrazones catalyzed by Rh complexes (Rh-Josiphos or Rh-Taniaphos) has been developed. The protocol can be applied to hydrazones with three different protective groups (Boc, Cbz, and methoxycarbonyl), allowing for selective deprotection and further elaboration of the hydrazine products in the presence of other functional groups.
Rhodium-Catalyzed Oxidative Cycloaddition of <i>N</i>
-<i>tert</i>
-Butoxycarbonylhydrazones with Alkynes for the Synthesis of Functionalized Pyrroles <i>via</i>
C(<i>sp</i>
<sup>3</sup>
)-H Bond Functionalization
作者:Chun-Ming Chan、Zhongyuan Zhou、Wing-Yiu Yu
DOI:10.1002/adsc.201600900
日期:2016.12.22
The reaction features a regioselective α‐imino alkyl C(sp3)−H bond functionalization resulting in selective formation of highlyfunctionalized NH‐free pyrroles. Our studies showed that utilizing the N‐tert‐butoxycarbonyl (N‐Boc) as the oxidizing directing group is critical for achieving the observed pyrrole formation versus the isoquinoline formation. To account for the pyrrole formation, we hypothesized
A C–H activation-based strategy has been developed for the synthesis of N-amino azaheterocycles. Rh(III)-catalyzed coupling of N-Boc hydrazones/N-Boc hydrazines with diazodiesters/diazoketoesters provides convenient access to synthetically and medicinally important compounds, N-amino isoquinolin-3-ones and N-amino indoles, by harnessing N-tert-butyloxycarbonyl (N-Boc) cleavage as an adaptable reactivity
Pd(ii)-catalyzed direct C–H acylation of N-Boc hydrazones with aldehydes: one-pot synthesis of 1,2-diacylbenzenes
作者:Satyasheel Sharma、Aejin Kim、Jihye Park、Mirim Kim、Jong Hwan Kwak、Young Hoon Jung、Jung Su Park、In Su Kim
DOI:10.1039/c3ob41644e
日期:——
A palladium(II)-catalyzed directacylation of acetophenone N-Boc hydrazones with aldehydes via C–H bond activation is described. This protocol provides direct access to a range of 1,2-diacylbenzenes, which are useful precursors to construct biologically interesting and pharmaceutically important compounds.
Pd-Catalyzed Carbonylations of Aryl/Heteroaryl Halides in Aqueous Micellar Media
作者:Juan C. Caravez、Madison J. Wong、Rahul D. Kavthe、Balaram S. Takale、Bruce H. Lipshutz
DOI:10.1021/acscatal.3c01757
日期:2023.9.15
Formation of amides, acids, and thioesters are readily fashioned from precursor aryl/heteroaryl halides under micellar catalysis conditions using W(CO)6 as a source of carbon monoxide. Loadings of ligated palladium catalysts are usually in the 0.5 mol % range. Yields with iodides tended to be higher than those using bromides. Applications to targets in the pharmaceutical industry are demonstrated,
Catalytic Enantioselective Hydrogenation of <i>N</i>-Alkoxycarbonyl Hydrazones: A Practical Synthesis of Chiral Hydrazines
作者:Naoki Yoshikawa、Lushi Tan、J. Christopher McWilliams、Deepa Ramasamy、Ruth Sheppard
DOI:10.1021/ol902602c
日期:2010.1.15
An enantioselective hydrogenation of hydrazones catalyzed by Rh complexes (Rh-Josiphos or Rh-Taniaphos) has been developed. The protocol can be applied to hydrazones with three different protective groups (Boc, Cbz, and methoxycarbonyl), allowing for selective deprotection and further elaboration of the hydrazine products in the presence of other functional groups.