Enriched13C NMR of a metallated α-sulphinyl ester; temperature effect
摘要:
AbstractLithium and magnesium enolates of an α‐sulphinyl ester 83% 13C enriched at C‐1 and C‐2 are studied by 13C NMR at different temperatures. It is shown that two metaliated species are present in the case of lithium which exchange at −60°C, ΔG≠ −60° = 37.8 KJ mol−1 (9.05 Kcal mol−1) and that there is no rapid exchange between the non‐metallated ester and the metallated species (on the NMR time scale). In the case of magnesium, two or three metallated species are formed, according to the temperature which do not exchange up to 0 °C.
The invention is directed to a process for the manufacture of pancreatic lipase-inhibiting oxetanone ethyl esters of the formula ##STR1## wherein X is undecyl or 2Z,5Z-undecadienyl; C.sub.6 is n-hexyl; Y is isobutyl and Z is formyl or Y is carbamoylmethyl and Z is acetyl; which process comprises esterifying the corresponding oxetanone ethanols, or hydrogenating the 3-undecenyl group in corresponding oxetanone ethyl ester starting materials to the undecyl group X, or N-formylating or N-acetylating corresponding primary amines.
Racemic compounds of the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and n are as described herein, enantiomers and diastereomers thereof, and salts of these esters with weak acids, are described. These compounds inhibit pancreas lipase and are useful agents in the treatment of obesity, hyperlipaemia, atherosclerosis and arteriosclerosis.
A Sulfoxide Reagent for One‐Pot, Three‐Component Syntheses of Sulfoxides and Sulfinamides**
作者:Fumito Saito
DOI:10.1002/anie.202213872
日期:2022.12.23
Upon Grignard reactions, a simple sulfoxide reagent allows the formation of sulfenate anions that are subsequently transformed into sulfoxides and sulfinamides. This one-pot, three-component method does not require substrates with preinstalled sulfur functional groups.
A Sulfur Monoxide Surrogate Designed for the Synthesis of Sulfoxides and Sulfinamides**
作者:David Austrup、Fumito Saito
DOI:10.1002/anie.202315123
日期:2023.12.18
A sulfinylhydrazine reagent for the synthesis of organosulfur(IV) functional groups is reported. The reagent is readily prepared from commercial starting materials and is amenable to thermal −S(O)− transfer to dienes. One-pot, three-component synthesis of sulfoxides and sulfinamides is further demonstrated by exploiting this reagent as an -S(O)- donor.
D The present invention relates to ion pair catalysts (I) comprising the cationic bisguanidinium ligand (A) and diperoxomolybdate anion (B). The present invention also relates to ion pair catalysts (III) comprising the cationic bisguanidinium ligand (C) and peroxotungstate anion (D). It further relates to the use of the said catalysts in the manufacture of enantiomerically enriched sulfoxides.
D 本发明涉及由阳离子双胍配体(A)和二氧钼酸阴离子(B)组成的离子对催化剂(I)。本发明还涉及由阳离子双胍配体(C)和过氧钨酸盐阴离子(D)组成的离子对催化剂(III)。本发明还涉及上述催化剂在制造对映体富集的硫氧化物中的用途。