Formation of a crystalline molecular complex between a chiral sulfoxide and a chiral amide

Tetrahedron Letters,Vo1.27,No.26,pp Printed in Great Britain

FORMATION

2989-2992,1986

OF A CRYSTALLINE A CHIRAL SULFOXIDE

P.Charpin#,

E.Dugach+,

0040-4039/86 $3.00 + .OO Pergamon Journals Ltd.

MOLECULAR COMPLEX BETWEEN AND A CHIRAL AMIDE H.B.Kagan+*,

F.R.Theobald

Institut de Chimie Moleculaire BBtiment 420 Universite Paris-Sud 91400 - Orsay. France

d'0rsay

Abstract (R)-methyl p-tolyl sulfoxide 2 and (S)-N-(3,5-dinitrobenzoyl)-I-phenyl complex. give a crystalline 1:l molecular The crystal ethylamine 1 Existence of hydrogen structure of-this complex is studied in detail. Its importance in the use bond between S=O and NH could be established. of (S) or (R)-1 as a chiral solvating agent for nmr determination of ee is briefly discussed. of sulfoxides During we

the course

used

some

chiral

the enantiomeric were performed use of

of our studies

purity with

ee of many

molecular

structure heavy-atom indicated appears

was

amide 1.

types

complex solved

in Table from

amino

as well. 1,

direct

by

Most et al.

have

for the nmr

reported

(MULTANS)

packing

bond

the isolation

crystal Patterson

and angles

of the complex

that one molecule

are

is shown.It

of j_ is

hydrogen

(N(3)-O(l)=2.S5(2yA). through NH to the S=O group of 2 bonded _______--__---__----_---_---------------------------------------------+ UA CNRS no255. Laboratoire de Synthese Asymetrique. # UA CNRS no331, DPC/SCM, CEN Saclay, 91191 Gif/Yvette.

2989

and (R)-2.

The

and the

lengths

the

determination

crystallization5.

methods

of

of the experiments

(S)-1 and sulfoxide

A few selected

structure

of sulfidesl*2

for the measurement

to report

between

and a partial

the crystal

Pirkle

We wish

was obtained using

agents

acid esters

a 1:l complex

oxidation

by nmr3.

Recently

of solutes4.

of

method

as solvating

of sulfoxides

of 3,5-dinitrobenzoyl

characterization The

amides

on asymmetric

2990

Planes II(1) and a(3) T(2)

is

from

almost

different

within

an adduct

perpendicular

molecules

are almost

to r(l) and

are almost

parallel

a(3).

parallel

whereas

Planes ~(1)

to each

other

plane

and

with

r(3)

distan-

ces between

the centroids ofn(l) and IT(~) of 3.84 i and 4.02 g giving a -> indeed the stacking of close to a : these phenyl planes is -> Such rather small distances between parallel phenyl a. groups

period along observed tional

the solid

in

state bring

intermolecular

which

appears

This

structure

interaction

to be a

charge

illustrates

between

transfer

in favour

these

between

groups

between

a chiral

sulfoxide

recent

example

is the crystal

and

a

chiral of 1:l

structure

of an in

addi-

solution,

J_ and 2.

one of the few examples

plexes

1,l

an argument

of molecular partner.

complex

com-

The

between

most 2

and

'-(binaphthol-2)9.

We

the successful

of sulfoxides

agent plexes The

that

assumed3

involving

isolation

was primarily

an hydrogen

for sulfoxides.

based

and suggests

We are presently

complex

bond

sulfoxides

and an acidic some

use of 1 as resolving

investigating

distances

this area.

1 (i) and angles

(01

:

1.52(2)

s - O(1)

:

C(1) - C(21)

:

1.485(15)

s - C(10)

: 1.736(11)

C(1)

- N(3)

:

1.449(14)

s

:

N(3)

- C(3)

:

1.353(13)

C(10)

- s - O(1)

:

C(3)

- O(3)

:

1.247(14)

C(10)

- s - C(l1)

:

:

1.448(14)

O(1)

C(1)

- C(2)

C(3) - C(31)

solvating

of weak

(S)-l_/(R)-2 gives

a potential

TABLE Selected

of 1 as chiral

on the formation

bond betwen

of the molecular

to this hypothesis

utilization

-

C(11)

1.462(8)

1.806(10)

- s - C(11)

:

108.0(5) 98.9(5) 105.5(5)

comNH.

support agent

2991

Representation of the 1:l complex S=O'"HN hydrogen bond.

Crystal

packing

showing

the

2992

Acknowledgments We

thank

drawings. Uclaf

CNRS

for

financial

One of us (E.D.)

support

and Dr D.

acknowledges

Vigner

a fellowship

for

from

the

the Roussel-

Company.

References

(1)

Pitchen,P. ; J.Am.Chem.Soc.,

(2)

Duzach,E.

; Kagan,H.B.,

(3) Deshmukh,M.N. Lett ., 1984, (4) Pirkle,W.H.

and notes

Ducach,E. Deshmukh,M.N. 1984, 106, '8188. Nouv.J.Chim.,

* Dugach,E. 3i67.

; Jugb,S.

; Tsipoures,A.,

1985,

;

Kagan,H.B.,

9,

1.

; Kagan,H.B.,

Tetrahedron

Lett.,

Tetrahedron

1985,

2989.

in (5) Amide (S)-l,[a]D = + 48.8oC (c=l, acetone), crystallization methanol, mp : 154oC and 159oC. Sulfoxide (R)-2, [c~]D = +142.6oC (c=l, acetone), crystallization in hexane, mp 750C. 15.9 mg (0.1 31.5 mg (0.1 mmol) of (S)-1 and mmol) of cyclohexane:ethyl (R)-2 were dissolved in 2 mL-of acetate (1:l). A slow evaporation of solvent allowed the formation of long colorless needles6, mp : 130°C.[~]~ = + 75.7OC (c=O.2, acetone). : C23H23N308S = 469.52 (6) Analysis N = 8.95 Calc. % : C = 58.84 H = 4.94 N = 8.88 Found % : C = 58.84 H = 4.91

0 = 20.45 0 = 20.47

S = 6.83 S = 6.83.

space group P21, (7) Crystal data : monoclinic, b = 6.848(7), c = 21.945(9),8 = 98.34(3), V a = = 1161(2) 7*808(~~: Z = 2,D, = 1.343 Mg m-3. and weighted Final R factor =X(/I\F, 1 - IFclf)/C\FoI = 0.064 after refineWR factor = 0.066 (unit weights) were obtained ment for 1466 unique reflections. (B)Germain,G. Main,P. ; Woolfson,N.M. ; MULTAN, crystal program fo; the automatic solution of University of York, 1973. (9)Toda.F.

; Tanaka,K.

; Mak,T.C.W.,

(Received in France 25 April 1986)

Chem.Lett.,

1984 -9

ORTEP

a computer structures. 2085.